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Engine Controls - System & Component Testing - 4 Cyl & V6: Other Nissan Altima L31

Testing & Diagnostics 64 illustrations ~33046 words

AIR INDUCTION SYSTEMS

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS . Also see WIRING DIAGRAMS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For vacuum diagram identification, see VACUUM DIAGRAMS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS .

Altima & Sentra (2.5L)

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 4.
  2. On CONSULT-II, from ACTIVE TEST mode, select VIAS SOL VALVE. Using CONSULT-II, turn Variable Induction Air Control System (VIAS) On and Off while observing power valve actuator rod. If rod moves as specified, testing is complete. If rod does not move, go to next step.
  3. Turn ignition off. Disconnect vacuum hose to VIAS power valve. Start engine and allow to idle. Check vacuum while using CONSULT-II to turn VIAS On and Off. When VIAS is On vacuum should exist at hose. When VIAS is Off vacuum should not exist. If vacuum exists as specified, repair or replace VIAS power valve actuator. If vacuum does not exist, go to step 6.
  4. Start engine and warm to normal operating temperature. While quickly increasing engine speed to 5000 RPM, check if power valve actuator rod moves. (Scheme 131) If rod moves, testing is complete. If rod does not move, go to next step.
  5. Turn ignition off. Disconnect vacuum hose to VIAS power valve. Disconnect VIAS control solenoid valve 2-pin harness connector. Start engine and allow to idle. Using 2 jumper wires, jumper VIAS control solenoid valve pin No. 1 to battery voltage and pin No. 2 to ground. When voltage is applied to solenoid, vacuum should exist at hose. When voltage is removed, vacuum should not exist. If vacuum exists as specified, repair or replace VIAS power valve actuator. If vacuum does not exist, go to next step.
  6. Turn ignition off. Check for cracks, clogging, poor or disconnected vacuum hoses and tubes between intake manifold and power valve actuator. If no problem is found, go to next step. If problem is found, repair or replace hoses as necessary.
  7. Check vacuum tank. Disconnect vacuum hoses from vacuum storage tank. Storage tank is located on intake manifold. Using hand-held vacuum pump apply vacuum to one port of storage tank and verify that vacuum exists at other port. If no problem is found, go to next step. If problem is found, replace vacuum storage tank.
  8. Turn ignition off. Disconnect VIAS control solenoid valve 2-pin harness connector. Turn ignition on. Measure voltage between ground and VIAS control solenoid valve harness connector terminal No. 1 (Red/Yellow wire on Altima; Green/White wire on Sentra). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 10.
  9. On Sentra, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E9 and F47. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector E103. Check fuse block fuse No. 20 (10-amp). Check for continuity in Green/White wire between fuse block fuse No. 20 and VIAS control solenoid valve. If problem is found, repair as necessary. After repair, retest system. On Altima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and F32. Check for poor, loose, corroded or damaged terminal connections in Intelligent Power Distribution Module (IPDM) harness connector E124. Check fuse block fuse No. 44 (10-amp). Check for continuity in Red/Yellow wire between fuse block fuse No. 44 and VIAS control solenoid valve.
  10. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132)or (Scheme 133). Check continuity in Yellow/Green wire between VIAS control solenoid valve harness connector terminal No. 2 and ECM harness connector terminal No. 16. (Scheme 134) Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. After repair, retest system.
  11. Check VIAS control solenoid valve. See «VIAS CONTROL SOLENOID VALVE»(ref-135812-S03372071982002103100000). If no problem is found, go to next step. If problem is found, replace VIAS control solenoid valve.
  12. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 131

Scheme 131
Scheme 131

Scheme 132

Scheme 132
Scheme 132

Scheme 133

Scheme 133
Scheme 133

Scheme 134

Scheme 134
Scheme 134

Altima (3.5L), I35, Maxima, Pathfinder & QX4

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 4.
  2. On CONSULT-II, from ACTIVE TEST mode, select VIAS SOL VALVE. Using CONSULT-II, turn Variable Induction Air Control System (VIAS) On and Off while observing power valve actuator rod. VIAS power valve is located on front of right cylinder head. If rod moves as specified, testing is complete. If rod does not move, go to next step.
  3. Turn ignition off. Disconnect vacuum hose to VIAS power valve. Start engine and allow to idle. Check vacuum while using CONSULT-II to turn VIAS On and Off. When VIAS is On, vacuum should exist at hose. When VIAS is Off, vacuum should not exist. If vacuum exists as specified, repair or replace VIAS power valve actuator. If vacuum does not exist, go to step 6.
  4. Start engine and warm to normal operating temperature. While quickly increasing engine speed to 5000 RPM, check if power valve actuator rod moves. (Scheme 135)- (Scheme 137). If rod moves, system is okay. If rod does not move, go to next step.
  5. Turn ignition off. Disconnect vacuum hose to VIAS power valve. Disconnect VIAS control solenoid valve 2-pin harness connector. (Scheme 138)- (Scheme 140). Start engine and allow to idle. Using 2 jumper wires, jumper VIAS control solenoid valve pin No. 1 to battery voltage and pin No. 2 to ground. When voltage is applied to solenoid, vacuum should exist at hose. When voltage is removed, vacuum should not exist. If vacuum exists as specified, repair or replace VIAS power valve actuator. If vacuum does not exist, go to next step.
  6. Turn ignition off. Check for cracks, clogging, poor or disconnected vacuum hoses and tubes between intake manifold and power valve actuator. If no problem is found, go to next step. If problem is found, repair or replace hoses as necessary.
  7. Check vacuum tank. Disconnect vacuum hoses from vacuum storage tank. Storage tank is located on intake manifold. Using hand-held vacuum pump apply vacuum to one port of storage tank and verify that vacuum exists at other port. If no problem is found, go to next step. If problem is found, replace vacuum storage tank.
  8. Turn ignition off. Disconnect VIAS control solenoid valve 2-pin harness connector. (Scheme 138)- (Scheme 140). Turn ignition on. Measure voltage between ground and VIAS control solenoid valve harness connector terminal No. 1 (Red/Yellow wire). See «WIRING DIAGRAMS»(ref-135817) article. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 10.
  9. On Altima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and F32. Check for poor, loose, corroded or damaged terminal connections in Intelligent Power Distribution Module (IPDM) harness connector E124. Check fuse block fuse No. 44 (10-amp). Check for continuity in Red/Yellow wire between fuse block fuse No. 44 and VIAS control solenoid valve. On I35 and Maxima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M161 and F68. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M19. Check fuse block fuse No. 20 (15-amp). Check for continuity in Red/Yellow wire between fuse block fuse and VIAS control solenoid valve. On Pathfinder and QX4, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M161 and F68. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M19. Check fuse block fuse No. 20 (15-amp). Check for continuity in Red/Yellow wire between fuse block and VIAS control solenoid valve. If problem is found, repair as necessary. After repair, retest system.
  10. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM locations (Scheme 133), (Scheme 141) or (Scheme 142). Check continuity of Yellow/Green wire between VIAS control solenoid valve harness connector terminal No. 2 and ECM harness connector terminal No. 16 (Pathfinder and QX4) or No. 27 (Altima, I35 and Maxima). (Scheme 134) Also, check circuit for short to ground and short to voltage. If problem is found, repair circuit as necessary. After repair, retest system. If no problem is found, go to next step.
  11. Reconnect all harness connectors. Repeat steps 2 or 4 as needed. If power valve actuator rod moves, test is complete. If power valve actuator rod does not move, go to next step.
  12. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 135

Scheme 135
Scheme 135

Scheme 136

Scheme 136
Scheme 136

Scheme 137

Scheme 137
Scheme 137

Scheme 138

Scheme 138
Scheme 138

Scheme 139

Scheme 139
Scheme 139

Scheme 140

Scheme 140
Scheme 140

Scheme 141

Scheme 141
Scheme 141

Scheme 142

Scheme 142
Scheme 142

VIAS Control Solenoid Valve

  1. With CONSULT-II Disconnect vacuum hoses from VIAS control solenoid valve. Turn ignition on. On CONSULT-II from ACTIVE TEST mode, select VIAS SOL VALVE. Using CONSULT-II, command valve On and Off. Using an auxiliary length of vacuum hose connected to vacuum port "A" blow through valve under specified conditions. See «CHECKING VIAS CONTROL SOLENOID VALVE WITH CONSULT-II»(ref-135812-S36951555392002103100000) table. (Scheme 143) If valve does not test as specified, replace VIAS control solenoid valve. CHECKING VIAS CONTROL SOLENOID VALVE WITH CONSULT-II VIAS Valve Condition Air Passage Continuity Between A & B Air Passage Continuity Between A & C ON Yes No OFF No Yes
  2. Without CONSULT-II Disconnect vacuum hoses from VIAS control solenoid valve. Turn ignition on. Using 2 jumper wires, jumper VIAS control solenoid valve pin No. 1 to battery voltage and pin No. 2 to ground. Using an auxiliary length of vacuum hose connected to vacuum port "A" blow through valve under specified conditions. When voltage is applied to solenoid, air continuity should exist between vacuum ports "A" and "B", and air continuity should not exist between vacuum ports "A" and "C". When voltage is removed from valve air continuity should exist between vacuum ports "A" and "C", and air continuity should not exist between vacuum ports "A" and "B". When voltage is removed, vacuum should not exist. (Scheme 143) If valve does not test as specified, replace VIAS control solenoid valve.

Scheme 143

Scheme 143
Scheme 143

COMPUTERIZED ENGINE CONTROLS

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

Power & Ground Circuits (Altima 2.5L)

  1. Start engine. If engine starts, go to step 6. If engine does not start, turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminal No. 42 (Red wire). For ECM location (Scheme 133) For ECM terminal identification (Scheme 134) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 3.
  2. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F59 and M71. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M4. Check fuse block fuse No. 1 (10-amp). Check for open or short in circuits between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system.
  3. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Check for continuity between ground and ECM harness connector terminals No. 59, 60, 106 and 108 (all wire are Black). (Scheme 134) If continuity does not exist, go to next step. If continuity exists, go to step 5.
  4. Check following: Check for poor, loose, corroded or damaged terminal connections in joint connector-5. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in ECM ground circuits between ground and ECM. If problem is found, repair as necessary. After repair, retest system. If no problem is found, connect ECM harness connector and go to next step
  5. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 12 (Red wire). (Scheme 134) If battery volage exists, check ignition signal. Perform appropriate procedure under «IGNITION SIGNAL CIRCUITS»(ref-135812-S08314156522002022500000). If battery voltage does not exist, go to next step.
  6. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 109 and 111 (Red/Green wires). Battery voltage should exist at each terminal for a few seconds after ignition is turned off. If battery voltage exists for a few seconds, go to next step. If battery voltage does not exist, go to step 9. If battery voltage exists after a few seconds, go to step 17.
  7. Disconnect Intelligent Power Distribution Module (IPDM) 12-pin harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of Red wire between ECM harness connector terminal No. 12 and IPDM harness connector terminal No. 35. (Scheme 134)and (Scheme 144). Continuity should exist. Also, check circuit for short to ground or short to voltage. If no problem is found, go to step 17. If problem is found, go to next step.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and F32. Check for open, short to ground or short to voltage in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system.
  9. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 20 (White/Black wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step 12.
  10. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Check for continuity in Red/Green wires between ground and ECM harness connector terminals No. 109 and 111 and IPDM harness connector terminal No. 33. (Scheme 134)and (Scheme 144). Continuity should exist. Also check circuits for short to ground or short to voltage. If continuity does not exist on all wires, go to next step. If continuity exists on any wire, go to step 12.
  11. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and F32. Check for open, short to ground or short to voltage in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system.
  12. Disconnect Intelligent Power Distribution Module (IPDM) harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of White/Black wire between ECM harness connector terminal No. 20 and IPDM harness connector terminal No. 44. (Scheme 134) and (Scheme 144). Continuity should exist. Also, check circuit for short to ground or short to voltage. If no problem is found, go to step 17. If problem is found, go to next step.
  13. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and F32. Check for open, short to ground or short to voltage in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system.
  14. Check IPDM fuse NO. 51 (15-amp). If fuse is not blown, go to step 17. If fuse is blown, replace fuse. After repair, retest system.
  15. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Check for continuity between ground and ECM harness connector terminals No. 59, 60, 106 and 108 (all wire are Black). (Scheme 134) Continuity should exists on all wires. Also, check circuits for short to voltage. If problem is found, go to next step. If no problem is found, go to step 17.
  16. Check following: Check for poor, loose, corroded or damaged terminal connections in joint connector-5. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ground and ECM. If problem is found, repair as necessary. After repair, retest system.
  17. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair as necessary. After repair, retest system. If no problem is found, replace IPDM.

Scheme 144

Scheme 144
Scheme 144

Power & Ground Circuits (Altima 3.5L)

  1. Start engine. If engine starts, go to step 6. If engine does not start, go to next step.
  2. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminal No. 43 (Red wire). (Scheme 134) If battery voltage exists, go to step 4. If battery voltage does not exist, go to next step.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M71 and F59. See «WIRING DIAGRAMS»(ref-135817). Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M4. Check fuse block fuse No. 1 (10-amp). Check for open or short in Red wire between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located behind glove box. (Scheme 133) Check continuity between ground and specified circuits. See «CHECKING ECM GROUND CIRCUITS»(ref-135812-S24134665432002102800000) table. Continuity should exist at each measurement. Also, check each circuit for short to voltage. If no problem is found, connect ECM harness connector and go to next step. If problem is found, repair as necessary. After repair, retest system. CHECKING ECM GROUND CIRCUITS Measure Between Ground & Terminal No. Wire Color 48 Black 57 Black 106 Black 108 Black
  5. Measure voltage between ground and ECM harness connector terminal No. 31 (Red wire). If battery voltage exists, check ignition signal. Perform appropriate procedure under «IGNITION SIGNAL CIRCUITS»(ref-135812-S08314156522002022500000). If battery voltage does not exist, go to next step.
  6. Turn ignition switch on, and then off. Backprobing at ECM, measure voltage between ground and ECM harness connector terminal No. 110 and 112 (both wires are Red/Green). (Scheme 134) Battery voltage should exist for a few seconds after ignition is turned off. If battery voltage exists for a few seconds, go to next step. If battery voltage does not exist, go to step 9. If battery voltage exists after a few seconds, go to step 16.
  7. Disconnect ECM 116-pin harness connector. ECM is located behind glove box. Disconnect Intelligent Power Distribution Module (IPDM) harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of Red wire between ECM harness connector terminal No. 31 and IPDM harness connector terminal No. 35. (Scheme 134)and (Scheme 144). Continuity should exist. Also, check circuit for short to ground or short to voltage. If no problem is found, go to step 16. If problem is found, go to next step.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and E32. Check for open or short in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system.
  9. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 38 (White/Black wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step 12.
  10. Disconnect ECM 116-pin harness connector. ECM is located behind glove box. Disconnect Intelligent Power Distribution Module (IPDM) harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of Red/Green wire between ECM harness connector Nos. 110 and 112 and IPDM harness connector terminal No. 33. (Scheme 134)and (Scheme 144). Continuity should exist. Also, check circuit for short to ground or short to voltage. If no problem is found, go to step 15. If problem is found, go to next step.
  11. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and E32. Check for open or short in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system.
  12. Disconnect ECM 116-pin harness connector. ECM is located behind glove box. Disconnect Intelligent Power Distribution Module (IPDM) harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of White/Black wire between ECM harness connector terminal No. 38 and IPDM harness connector terminal No. 44. (Scheme 134)and (Scheme 144). Continuity should exist. Also, check circuit for short to ground or short to voltage. If no problem is found, go to step 14. If problem is found, go to next step.
  13. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and E32. Check for open or short in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system.
  14. Check IPDM fuse No. 51 (15-amp). If fuse is not blown, go to step 16. If fuse is blown, replace fuse. After repair, retest system.
  15. Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located behind glove box. Check continuity between ground and specified circuits. See «CHECKING ECM GROUND CIRCUITS»(ref-135812-S24134665432002102800000) table. Continuity should exist. Also, check each circuit for short to voltage. If no problem is found, connect ECM harness connector and go to next step. If problem is found, repair as necessary. After repair, retest system.
  16. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair as necessary. After repair, retest system. If no problem is found, replace IPDM.

Power & Ground Circuits (Frontier 2.4L & Xterra 2.4L)

  1. Start engine. If engine starts, go to step 4. If engine does not start, go to next step.
  2. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminal No. 24 (White/Green wire) (Scheme 145)and (Scheme 146). If battery voltage exists, go to step 12. If battery voltage does not exist, go to next step.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E43 and M65. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M59 and F27. Check for poor, loose, corroded or damaged terminal connections in fuse block junction connector E49. Check fuse block fuses No. 13 (10-amp) and 27 (10-amp). Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 80 (Sky Blue wire). If battery voltage exists, go to step 6. If battery voltage does not exist, go to next step.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M81 and F36. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M27. Check fuse block fuses No. 13 (10-amp) and 27 (10-amp). Check for open or short in circuits between ECM and fuses. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ECM terminals No. 67, 72 and 117 (Black/Pink wires). Battery voltage should exist at each terminal for a few seconds after ignition is turned off. If battery voltage exists for a few seconds, go to step 12. If battery voltage does not exist, go to next step. If battery voltage exists after a few seconds, go to step 11.
  7. Turn ignition off. Disconnect ECM 124-pin harness connector. ECM is located below instrument cluster. Remove lower instrument panel to access ECM. Disconnect ECM relay harness connector. ECM relay is mounted on bracket under instrument panel next to ECM. Check continuity in circuits between ECM harness connector terminals No. 67, 72 and 117 (all Black/Pink wires) and ECM relay harness connector terminal No. 3. (Scheme 146)and (Scheme 147). Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, leave harness connectors disconnected and go to next step.
  8. Measure volage between ground and ECM relay harness connector terminals No. 2 and then No. 5 (both wires are Sky Blue). If battery voltage exists at both terminals, go to step 10. If battery voltage does not exist at both terminals, go to next step.
  9. Check for open or short in Sky Blue wires between ECM relay and in-line harness connector F36. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  10. Turn ignition off. Disconnect ECM 124-pin harness connector. ECM is located below instrument cluster. Remove lower instrument panel to access ECM. Check continuity in Orange/Black wire between ECM harness connector terminal No. 4 and ECM relay harness connector terminal No. 1. (Scheme 146)and (Scheme 147). Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, repair as necessary. After repair, retest system.
  11. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 147) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. Replace relay, if test values are not as specified.
  12. Turn ignition off. Disconnect ECM 124-pin harness connector. ECM is located below instrument cluster. Remove lower instrument panel to access ECM. Check continuity between ground and ECM harness connector terminals No. 10, 19, 116 and 124 (Black/Red wire), and No. 25 and 32 (Black/Yellow wire). See «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist. Also, check circuits for short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  13. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 145

Scheme 145
Scheme 145

Scheme 146

Scheme 146
Scheme 146

Scheme 147

Scheme 147
Scheme 147

Power & Ground Circuits (Frontier 3.3L & Xterra 3.3L)

  1. Start engine. If engine starts, go to step 6. If engine does not start, go to next step.
  2. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminal No. 24 (White/Blue wire) (Scheme 145)and (Scheme 146). If battery voltage exists, go to step 4. If battery voltage does not exist, go to next step.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E74 and M82. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M59 and F27. Check for poor, loose, corroded or damaged terminal connections in fuse block junction connector E49. Check fuse block fuses No. 13 (10-amp) and 27 (10-amp). Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Disconnect ECM 124-pin harness connector. ECM is located below instrument cluster. Remove lower instrument panel to access ECM. (Scheme 145) Check continuity between ground and ECM harness connector terminals No. 10, 19, 116 and 124 (Black/Red wire). (Scheme 146) Check continuity between ground and ECM harness connector terminals No. 25 and 32 (Black/Yellow wire). Continuity should exist at all measurements. Also, check circuits for short to voltage. If problem is found, go to next step. If no problem is found, go to step 15.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in joint connector-2. See «WIRING DIAGRAMS»(ref-135817) article. Check for open in ground circuits between ground and ECM. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 80 (Sky Blue wire). (Scheme 146) If battery voltage exists, go to step 8. If battery voltage does not exist, go to next step.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M59 and F27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M27. Check fuse block fuses No. 13 (10-amp) and 27 (10-amp). Check for open or short in circuits between ECM and fuses. If problem is found, repair as necessary. After repair, retest system.
  8. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ECM terminals No. 67, 72 and 117 (Black/Pink wires). Battery voltage should exist at each terminal for a few seconds after ignition is turned off. If battery voltage exists for a few seconds, go to step 14. If battery voltage does not exist, go to next step. If battery voltage exists after a few seconds, go to step 13.
  9. Disconnect ECM relay harness connector. ECM relay is mounted on bracket under instrument panel next to ECM. (Scheme 145) Measure volage between ground and ECM relay harness connector terminals No. 2 and then No. 5 (both wires are Sky Blue). (Scheme 146) If battery voltage does not exist at both terminals, go to next step. If battery voltage exists at both terminals, go to step 11.
  10. Check for open or short in Sky Blue wires between ECM relay and in-line harness connector F27. If problem is found, repair as necessary. After repair, retest system.
  11. Turn ignition off. Disconnect ECM 124-pin harness connector. ECM is located below instrument cluster. Remove lower instrument panel to access ECM. (Scheme 145) Check continuity in Orange/Black wire between ECM harness connector terminal No. 4 and ECM relay harness connector terminal No. 1. (Scheme 146)and (Scheme 147). Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, leave ECM harness connector disconnected and go to next step.
  12. Check continuity in circuits between ECM harness connector terminals No. 67, 72 and 117 (all Black/Pink wires) and ECM relay harness connector terminal No. 3. Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, leave ECM harness connector disconnected and go to next step.
  13. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 147) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. Replace relay, if test values are not as specified.
  14. Turn ignition off. Disconnect ECM 124-pin harness connector. ECM is located below instrument cluster. Remove lower instrument panel to access ECM. (Scheme 145) Check continuity between ground and ECM harness connector terminals No. 10, 19, 116 and 124 (Black/Red wire). (Scheme 146) Check continuity between ground and ECM harness connector terminals No. 25 and 32 (Black/Yellow wire). Continuity should exist. Also, check circuits for short to voltage. If no problem is found, go to next step. If problem is found, go to step 5.
  15. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Power & Ground Circuits (I35 & Maxima)

  1. Start engine. If engine starts, go to step 11. If engine does not start, go to next step.
  2. Turn ignition off and on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 43 (Red wire). (Scheme 134)and (Scheme 141). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 4.
  3. Check following: Check fuse block fuse No. 17 (10-amp). Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M161 and F68. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M19 and E89. Check for open or short in circuits between ECM and ignition switch. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located under instrument panel. (Scheme 141) Check continuity between ground and ECM harness connector terminals No. 48, 57, 106 and 108 (Black wires). (Scheme 134) Continuity should exist. Also, check circuits for short to voltage. If problem is found, repair as necessary. After repair, retest system.
  5. Remove ECM relay from relay panel. (Scheme 148) Measure voltage between ground and ECM relay harness connector terminals No. 2 (White/Blue wire) and No. 6 (Purple wire). (Scheme 149) If battery voltage does not exist, go to next step. If battery voltage exists, leave harness connectors disconnected and go to step 7.
  6. Check following: Check fuse block fuses No. 58 and 59 (15-amp). Check for poor, loose, corroded or damaged terminal connections in joint connector-12. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM and ECM relay. If problem is found, repair as necessary. After repair, retest system.
  7. Check continuity of White/Black wire (changes to White/Red at relay) between ECM harness connector terminal No. 38 and ECM relay harness connector terminal No. 1. (Scheme 134)and (Scheme 149). Also, check circuit for short to ground and short to voltage. If no problem is found, check ignition signal. Perform appropriate procedure under «IGNITION SIGNAL CIRCUITS»(ref-135812-S08314156522002022500000). If problem is found, go to next step.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E15 and F18. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM and ECM relay. If problem is found, repair as necessary. After repair, retest system.
  9. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ground and ECM terminals No. 31 (Red wires) and then No. 110 and 112 (Red/Green wires). Battery voltage should exist at each terminal for a few seconds after turning ignition off, then drop to about zero volts. If voltage is as specified, go to step 15. If battery voltage does not exist, go to next step. If battery voltage exists for more than a few seconds, go to step 12.
  10. Remove ECM relay from relay panel. (Scheme 148) Measure voltage between ground and ECM relay harness connector terminals No. 3 (White/Blue wire). (Scheme 149) If battery voltage exists, leave ECM relay disconnected and go to step 12. If battery voltage does not exist, go to next step.
  11. Check following: Check for poor, loose, corroded or damaged terminal connections in joint connector-12. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM relay and fuses. If problem is found, repair as necessary. After repair, retest system.
  12. Check continuity of specified circuits between ECM relay and ECM. See «CHECKING ECM RELAY CIRCUIT VOLTAGE (I35 & MAXIMA)»(ref-135812-S39995124842002102900000) table. (Scheme 134)and (Scheme 149). Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 14. CHECKING ECM RELAY CIRCUIT VOLTAGE (I35 & MAXIMA) ECM Terminal ECM Relay Terminal Wire Color 31 7 Red/White 110 & 112 5 Red/Green
  13. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E15 and F18. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM relay and ECM. If problem is found, repair as necessary. After repair, retest system.
  14. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 149) When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  15. Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located under instrument panel. Check continuity between ground and ECM harness connector terminals No. 48, 57, 106 and 108 (Black wires). (Scheme 134) Continuity should exist. Also, check circuits for short to voltage. If problem is found, repair as necessary. After repair, retest system.
  16. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 148

Scheme 148
Scheme 148

Scheme 149

Scheme 149
Scheme 149

Power & Ground Circuits (Pathfinder & QX4)

  1. Start engine. If engine starts, go to step 11. If engine does not start, go to next step.
  2. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 43 (Red wire). (Scheme 134)and (Scheme 142). If battery voltage exists, go to step 4. If battery voltage does not exist, go to next step.
  3. Check following: Check fuse block fuse No. 21 (10-amp). Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M33 and F22. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M10 and E4. Check for open or short in circuits between ECM and ignition switch. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Check continuity between ground and ECM harness connector terminals No. 48, 57, 106 and 108 (Black wires). (Scheme 134) Continuity should exist. Also, check circuits for short to ground or short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, leave harness connector disconnected and go to next step.
  5. Remove ECM relay. (Scheme 150) Measure voltage between ground and ECM relay harness connector terminals No. 1 (White/Red wire) and No. 5 (Red/White wire). (Scheme 149) If battery voltage does not exist, go to next step. If battery voltage exists, leave relay and harness connector disconnected and go to step 7.
  6. Check following: Check fuse block fuses No. 62 (7.5-amp) and No. 63 (10-amp). Check for open or short in circuits between ECM relay and battery. If problem is found, repair as necessary. After repair, retest system.
  7. Check continuity of Blue/Black wire between ECM relay harness connector terminal No. 2 and ECM harness connector terminal No. 26. (Scheme 134)and (Scheme 149). Continuity should exist. Also, check circuit for short to ground and short to voltage. If no problem is found, check ignition signal. See «IGNITION SIGNAL CIRCUITS»(ref-135812-S08314156522002022500000) under IGNITION SYSTEM. If problem is found, leave relay and harness connector disconnected and go to next step.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M32 and F23. Check for open or short in circuits between ECM relay and ECM. If problem is found, repair as necessary. After repair, retest system. If no problem is found, connect relay and harness connector and go to next step.
  9. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 67 (White/Red wire). (Scheme 134)and (Scheme 142). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 11.
  10. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M32 and F23. Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  11. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 110 and 112 (Black/White wires). Battery voltage should exist at each terminal for a few seconds after turning ignition off, then drop to about zero volts. If voltage is as specified, go to step 17. If battery voltage does not exist, go to next step. If battery voltage exists for more than a few seconds, go to step 14.
  12. Remove ECM relay. (Scheme 150) Measure voltage between ground and ECM relay harness connector terminal No. 7 (White/Red wire). (Scheme 149) If battery voltage does not exist, go to next step. If battery voltage exists, leave relay disconnected and go to step 14.
  13. Check for open or short in circuit between ECM relay and fuse block fuse No. 62. If fuse is blown, replace and retest system. If fuse is not blown, go to next step.
  14. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 12 (White/Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, leave relay disconnected and go to step 16.
  15. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M94 and F23. Check fuse block fuse No. 21. If problem is found, repair as necessary. After repair, retest system.
  16. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Check continuity of Black/White wire between ECM relay harness connector terminal No. 6 and ECM harness connector terminals No. 110 and 112. (Scheme 134)and (Scheme 149). Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. After repair, retest system.
  17. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M32 and F23. Check for open or short in circuits between ECM and ECM relay. If problem is found, repair as necessary. After repair, retest system.
  18. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 149) When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  19. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Check continuity between ground and ECM harness connector terminals No. 48, 57, 106 and 108 (Black wires). (Scheme 134) Continuity should exist. Also, check circuits for short to ground or short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, leave harness connector disconnected and go to next step.
  20. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 150

Scheme 150
Scheme 150

Power & Ground Circuits (Quest)

  1. Start engine. If engine starts, turn engine off and go to step 6. If engine does not start, go to next step.
  2. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 24 (Blue/Yellow wire). (Scheme 146)and (Scheme 151). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 4.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M42 and F104. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 4 (10-amp). Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 151) Check continuity between ground and ECM harness connector terminals No. 10, 19, 116 and 124 (Black wires) and No. 25 and 32 (Black/Red wires). Continuity should exist. (Scheme 146) Also, check harness for short to voltage. If problem is found, leave harness connector disconnected and go to next step. If no problem is found, go to step 15.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM and engine ground. If problem is found, repair as necessary. After repair, retest system. If no problem is found, connect ECM harness connector and go to next step.
  6. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 80 (Yellow wire). (Scheme 146) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E53 and F2. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 4 (10-amp). Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  8. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ground and ECM terminals No. 67, 72 and 117 (Black/White wires). Battery voltage should exist at each terminal for a few seconds after turning ignition off, then drop to about zero volts. If voltage is as specified, go to step 14. If battery voltage does not exist, go to next step. If battery voltage exists for more than a few seconds, go to step 13.
  9. Disconnect ECM relay. For ECM relay location (Scheme 151) Measure voltage between ground and ECM relay harness connector terminals No. 2 and 3 (Red wires). (Scheme 147) If battery voltage does not exist, go to next step. If battery voltage exists, leave relay disconnected and go to step 11.
  10. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E53 and F2. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 4 (10-amp). Check for open or short in circuits between ECM and battery. If problem is found, repair as necessary. After repair, retest system.
  11. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 151) Check continuity in White/Green wire between ECM harness connector terminal No. 4 and ECM relay harness connector terminal No. 1. (Scheme 146)and (Scheme 147). Continuity should exist. Also, check circuit for short to ground and short to voltage. If no problem is found, leave harness connector disconnected and go to next step. If problem is found, repair as necessary. After repair, go to next step.
  12. Check continuity individually between ECM relay harness connector terminal No. 5 and ECM harness connector terminals No. 67, 72 and 117 (Black/White wires). Continuity should exist. Also, check circuit for short to ground or short to voltage. If no problem is found, leave relay and harness connector disconnected and go to next step. If problem is found, repair as necessary. After repair, retest system.
  13. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 147) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. Replace relay, if test values are not as specified.
  14. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 151) Check continuity between ground and ECM harness connector terminals No. 10, 19, 116 and 124 (Black wires). Also, check continuity between ground and ECM harness connector terminals No. 25 and 32 (Black/Red wires). Continuity should exist. (Scheme 146) Also, check harness for short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, go to next step.
  15. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 151

Scheme 151
Scheme 151

Power & Ground Circuits (Sentra 1.8L)

  1. Start engine. If engine starts, go to step 4. If engine does not start, go to next step.
  2. Turn ignition off, and then on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 43 (Black/Red wire). (Scheme 132)and (Scheme 134). If battery voltage exists, go to step 13. If battery voltage does not exist, go to next step.
  3. Check following: Check fuse block fuse No. 17 (10-amp). Check for poor, loose, corroded or damaged terminal connections in fuse block junction block harness connector M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E9 and F47. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M19 and E108. Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Backprobing at ECM, measure voltage between ground and ECM terminal No. 67 (White/Blue wire). (Scheme 134) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check fuse block fuse No. 17 (10-amp). Check for poor, loose, corroded or damaged terminal connections in fuse block junction block harness connector E24. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E9 and F47. Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ground and ECM terminals No. 110 and 112 (White wires). (Scheme 134) Battery voltage should exist at each terminal for a few seconds after turning ignition off. If voltage is as specified, go to step 13. If battery voltage does not exist, go to next step. If battery voltage exists for more than a few seconds, go to step 12.
  7. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Remove ECM relay from fuse and relay panel. For ECM relay location (Scheme 152) Check continuity of White wires between ECM harness connector terminals No. 110 and 112 and ECM relay harness connector terminal No. 5. (Scheme 134)and (Scheme 149). Continuity should exist. Also, check circuit for short to ground and short to voltage. If no problem is found, leave relay and harness connector disconnected and go to next step. If problem is found, repair circuit as necessary. After repair, retest system.
  8. Measure voltage between ground and ECM relay harness connector terminals No. 1 and 3 (White/Blue wires). If battery voltage does not exist, go to next step. If battery voltage exists, leave relay and harness connector disconnected and go to step 10.
  9. Check for open or short in circuits between ECM relay and fuse. See «WIRING DIAGRAMS»(ref-135817) article. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  10. Check continuity in White/Green wire between ECM harness connector terminal No. 31 and ECM relay harness connector terminal No. 2. Continuity should exist. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 12.
  11. Check for open or short in circuits between ECM relay and ECM. See «WIRING DIAGRAMS»(ref-135817) article. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  12. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 149) When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  13. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Check continuity between engine ground and ECM harness connector terminals No. 48 and 57 (Black wires) and No. 106 and 108 (Black/Yellow wires). Continuity should exist. Also, check circuits for short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  14. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 152

Scheme 152
Scheme 152

Sentra (2.5L)

  1. Start engine. If engine starts, go to step 9. If engine does not start, go to next step.
  2. Turn ignition off and on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 42 (Black/Red wire). (Scheme 132)and (Scheme 134). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 4.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M19 and E108. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E10 and F48. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors E112 and M1. Check fuse block fuse No. 17 (10-amp). Check for open or short in circuits between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located under instrument panel. (Scheme 132) Check continuity between ground and ECM harness connector terminal No. 59 (Black/Red wire). Check continuity between ground and ECM harness connector terminals, 60, 106 and 108 (Black wires). (Scheme 134) Continuity should exist at each measurement. Also, check circuits for short to voltage. If problem is found, go to next step. If no problem is found, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in joint connector-3. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ground and ECM. If problem is found, repair as necessary. After repair, retest system.
  6. Disconnect ECM relay. (Scheme 152) Measure voltage between ground and ECM relay harness connector terminals No. 1 (White/Blue wire) and No. 6 (Red/Black wire). (Scheme 149) If battery voltage does not exist, go to next step. If battery voltage exists, leave harness connectors disconnected and go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E9 and F47. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuses No. 34 and 36 (15-amp). Check for poor, loose, corroded or damaged terminal connections in underhood fuse and fusible link box harness connectors E22 and E24. Check for open or short in circuits between battery and ECM relay. If problem is found, repair as necessary. After repair, retest system.
  8. Check continuity of White/Green wire between ECM harness connector terminal No. 20 and ECM relay harness connector terminal No. 2. (Scheme 134)and (Scheme 149). Also, check circuit for short to ground and short to voltage. If no problem is found, check ignition signal. Perform appropriate procedure under «IGNITION SIGNAL CIRCUITS»(ref-135812-S08314156522002022500000). If problem is found, repair as necessary. After repair, retest system.
  9. Turn ignition on, and then off. Backprobing at ECM, measure voltage between ground and ECM terminals No. 12 (Red wire), and then No. 109 and 111 (Red/Green wires). Battery voltage should exist at each terminal for a few seconds after turning ignition off, then drop to about zero volts. If voltage is as specified, go to step 13. If battery voltage does not exist, go to next step. If battery voltage exists for more than a few seconds, go to step 12.
  10. Disconnect ECM relay. (Scheme 152) Measure voltage between ground and ECM relay harness connector terminals No. 3 (White/Blue wire). (Scheme 149) If battery voltage does not exist, go to next step. If battery voltage exists, leave ECM relay disconnected and go to step 12.
  11. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E9 and F47. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM relay and fuses. If problem is found, repair as necessary. After repair, retest system.
  12. Check continuity of specified circuits between ECM and ECM relay. See «CHECKING ECM RELAY CIRCUIT VOLTAGE (SENTRA 2.5L)»(ref-135812-S05031349202002111100000) table. (Scheme 134)and (Scheme 149). Also, check circuit for short to ground and short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system. CHECKING ECM RELAY CIRCUIT VOLTAGE (SENTRA 2.5L) ECM Terminal ECM Relay Terminal Wire Color 12 7 Red 109 & 111 5 Red/Green
  13. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 149) When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  14. Turn ignition off. Disconnect ECM 116-pin harness connector. ECM is located under instrument panel. (Scheme 132) Check continuity between ground and ECM harness connector terminal No. 59 (Black/Red wire). Check continuity between ground and ECM harness connector terminals, 60, 106 and 108 (Black wires). (Scheme 134) Continuity should exist at each measurement. Also, check circuits for short to voltage. If problem is found, go to next step. If no problem is found, go to step 16.
  15. Check following: Check for poor, loose, corroded or damaged terminal connections in joint connector-3. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ground and ECM. If problem is found, repair as necessary. After repair, retest system.
  16. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

EMISSION SYSTEMS & SUB-SYSTEMS

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

EXHAUST GAS RECIRCULATION

ECM controls EGR system based on engine operating conditions. ECM controls ground circuit for EGR Control (EGRC) solenoid opening and closing EGR valve as necessary. (Scheme 153) EGR-VCV or EGRC solenoid remains closed under certain conditions including the following

  1. Engine stopped.
  2. Engine starting.
  3. Engine idling.
  4. Low engine coolant temperature.
  5. Excessively high engine coolant temperature.
  6. High engine speed.
  7. Mass airflow sensor malfunction.

Scheme 153

Scheme 153
Scheme 153

EGR System Check

To test EGR function, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

EGR Backpressure Transducer

To test EGR backpressure transducer, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

EGRC Solenoid

To test EGR control solenoid, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

EGR Temperature Sensor

To test EGR temperature sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

EGR Valve

To test EGR function, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

EGR Volume Control Valve

To test EGR volume control valve, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

EVAPORATIVE EMISSIONS CONTROL SYSTEM

Note. For EVAP system component locations, see appropriate illustration in COMPONENT LOCATIONS .

Note. For vacuum hose and circuit identification, see VACUUM DIAGRAMS article.

Evaporative Emissions (EVAP) control system is used to reduce hydrocarbon (HC) emissions emitted into the atmosphere from the fuel system. Reduction of HC emissions is accomplished by activated charcoals in the EVAP canister. Fuel vapors from the fuel tank are stored in the EVAP canister when engine is not running and during refueling. Vapors are then purged into intake manifold while engine is running. EVAP canister purge volume is controlled by the ECM. EVAP canister purge is shut off during deceleration and idle periods.

EVAP Canister

Remove EVAP canister. See REMOVAL, OVERHAUL & INSTALLATION. Plug vent hose and blow air into port "A". Air should flow freely out of port "B". (Scheme 154) Replace EVAP canister, if operation is not as specified.

Scheme 154

Scheme 154: EVAP Canister
Scheme 154: EVAP Canister

EVAP Canister Purge Volume Control Solenoid Valve

To test EVAP canister purge volume control solenoid valve, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

Fuel Tank Temperature Sensor

To test Fuel Tank Temperature (FTT) sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

ON BOARD REFUELING VAPOR RECOVERY SYSTEM

When refueling vehicle, fuel tank pressure increases. When pressure reaches the setting value of the Refueling Control Valve (RCV) opening pressure, RCV opens. Allowing air and vapor pressure in fuel tank to pass through EVAP vapor cut valve into the EVAP canister. Where fuel vapors are absorbed by EVAP canister activated charcoal and air is purged to atmosphere. When during refueling process fuel tank becomes full, refueling EVAP vapor cut valve is closed and refueling is stopped by auto shut-off. Vapors stored while fueling are purged when vehicle is driven. RCV is closed during driving and EVAP system operates same as in conventional systems.

Strong Fuel Odor From EVAP Canister

WARNINGWhen conducting tests around open fuel tanks and containers observe following: Furnish work area with proper fire safety equipment. DO NOT smoke. Keep open flames and sparks away from work area.
CAUTIONBefore removing fuel lines or hoses, perform following procedures: Disconnect negative battery cable. Release fuel pressure. Place drained fuel into an explosion proof container and secure lid. Always replace any "O" ring seals when removed. Be careful to not twist or kink hoses or tube when they are installed. To avoid damage to hoses, DO NOT overtighten hose clamps. After repairs are completed, run vehicle and check for fuel leaks. DO NOT continue to top off fuel tank after fuel pump nozzle automatically shuts off.
  1. Remove EVAP canister along with EVAP canister vent control valve. Weigh EVAP canister with vent valve attached. If EVAP canister weighs less than 4 lbs. (1.8 kg), go to next step. If canister weighs more than specified, go to step 3 .
  2. If water drains from EVAP canister, go to next step. If no water drains from canister, go to step 6 .
  3. Replace EVAP canister. After repairs, go to next step.
  4. Check water separator. See «WATER SEPARATOR»(ref-135812-S13289957802002103100000) . If water separator test okay, go to next step. If water separator does not test okay, replace water separator.
  5. Check vacuum hose between EVAP canister and water separator for clogging or poor connections. If problem is found, replace vacuum hose. After repair, retest system.
  6. Check refueling EVAP vapor cut valve. See «REFUELING EVAP VAPOR CUT VALVE»(ref-135812-S07244383082002103100000) . If no problem is found, go to next step. If problem is found, replace refueling EVAP vapor cut valve.
  7. Check refueling control valve. See «REFUELING CONTROL VALVE»(ref-135812-S32292073562002103100000) . If no problem is found, testing is complete. If problem is found, replace refueling control valve.

Cannot Refuel/Strong Fuel Odor From Fuel Filler While Refueling

  1. Remove EVAP canister along with EVAP canister vent control valve. Weigh EVAP canister with vent valve attached. If EVAP canister weighs less than 4 lbs. (1.8 kg), go to next step. If canister weighs more than specified, go to step 3 .
  2. If water drains from EVAP canister, go to next step. If no water drains from canister, go to step 6 .
  3. Replace EVAP canister. After repairs, go to next step.
  4. Check water separator. See «WATER SEPARATOR»(ref-135812-S13289957802002103100000) . If water separator tests okay, go to next step. If water separator does not test okay, replace water separator.
  5. Check vacuum hose between EVAP canister and water separator for clogging or poor connections. If problem is found, replace vacuum hose. After repair, retest system.
  6. Check vent hoses and tubes between EVAP canister and refueling control valve for clogging, kinks, looseness or improper connections. If no problem is found, go to next step. If problem is found, repair or replace hoses or tubes as necessary.
  7. Check signal and recirculation lines for clogging, dents or cracks. If no problem is found, go to next step. If problem is found, repair as necessary.
  8. Check refuel control valve. See «REFUELING CONTROL VALVE»(ref-135812-S32292073562002103100000) . If no problem is found, go to next step. If problem is found, repair as necessary.
  9. Check refueling EVAP vapor cut valve. See «REFUELING EVAP VAPOR CUT VALVE»(ref-135812-S07244383082002103100000) . If no problem is found, go to next step. If problem is found, replace refueling EVAP vapor cut valve.
  10. Check fuel filler tube and hose between fuel tank and gas cap for clogging, dents or cracks. If no problem is found, go to next step. If problem is found, replace refueling EVAP vapor cut valve.
  11. Drain fuel from tank. Remove fuel filler tube and hose. Using a small wooden dowel, attempt to open one-way check valve. Check valve should open and close when pushed with dowel. Check one-way fuel check valve for sticking or clogging. If no problem is found, testing is complete. If problem is found, replace fuel tank along with check valve.

Refueling EVAP Vapor Cut Valve

With CONSULT-II

  1. Remove fuel tank.
  2. Drain fuel from fuel tank as follows: Remove fuel feed hose from fuel level sensor unit (on top of fuel tank). Connect a spare hose to fuel level sensor unit. On CONSULT-II, select ACTIVE TEST mode, and then FUEL PUMP RELAY. Activate fuel pump and capture fuel. When fuel tank is completely drained, go to next step.
  3. Check refueling EVAP vapor cut valve for being stuck by blowing air into refueling EVAP vapor cut valve from "B". (Scheme 155)or (Scheme 156). If air flows freely into fuel tank, go to next step. If air does not flow freely into fuel tank, replace fuel tank.
  4. Check EVAP vapor cut valve for being stuck open as follows: Connect vacuum pump to hose ends "A" and "B" using suitable 3-way connector. (Scheme 155)or (Scheme 156). On fuel tank, remove fuel level sensor unit retaining ring. When reassembling always replace "O" ring seal with NEW part. Place fuel tank upside down. Apply vacuum pressure to hose ends "A" and "B". With fuel level sensor unit opening free, ensure that vacuum holds at 3.94 Hg (13.3 kPa). If vacuum does not hold, replace fuel tank. If vacuum holds, refueling EVAP vapor cut valve is okay.

Without CONSULT-II

  1. Remove fuel tank.
  2. Drain fuel from tank as follows: Remove fuel level sensor unit retainer. Drain fuel from tank using a hand pump. When fuel tank is completely drained, go to next step.
  3. Check refueling EVAP vapor cut valve for being stuck by blowing air into refueling EVAP vapor cut valve from "B". (Scheme 155)or (Scheme 156). If air flows freely into fuel tank, go to next step. If air does not flow freely into fuel tank, replace fuel tank.
  4. Check EVAP vapor cut valve for being stuck open as follows: Connect vacuum pump to hose ends "A" and "B" using suitable 3-way connector. (Scheme 155)or (Scheme 156). On fuel tank, remove fuel level sensor unit retaining ring. When reassembling always replace "O" ring seal with NEW part. Place fuel tank upside down. Apply vacuum pressure to both hose ends "A" and "B". With fuel level sensor unit opening free, ensure that vacuum holds at 3.94 Hg (13.3 kPa). If vacuum does not hold, replace fuel tank. If vacuum holds, refueling EVAP vapor cut valve is okay.

Scheme 155

Scheme 155
Scheme 155

Scheme 156

Scheme 156
Scheme 156

Refueling Control Valve

Note. On Frontier, I35, Maxima, Sentra and Xterra, refueling control valve is not replaceable. If defective, fuel tank must be replaced.

Remove fuel filler cap. Check air continuity between hose ends "A" and "B". Blow air into hose end "B". (Scheme 155)or (Scheme 156). Air should flow freely into fuel tank. Blow air into hose "A". Air should not flow. Using a hand pressure pump with a vacuum "T", apply 2.9 psi (20 kPa) of pressure to hoses "A" and "B". Air should not escape. If operation is not as specified, replace fuel tank with refueling control valve. If operation is as specified, refueling control valve is okay.

Water Separator

Note. DO NOT attempt to disassemble water separator.

  1. Visually inspect water separator air inlet for insect nests.
  2. Visually inspect water separator for cracks or flaws in appearance.
  3. Visually inspect water separator for cracks or flaws in hoses.
  4. Check that "A" and "C" are not clogged by blowing air into "B" with "A" and "C" plugged. (Scheme 157) If problem is found, replace water separator.

Scheme 157

Scheme 157
Scheme 157

POSITIVE CRANKCASE VENTILATION

With engine idling, remove vent hose from PCV valve. A hissing noise should be heard. Strong vacuum should be felt immediately when a finger is placed over valve inlet. Clean or replace PCV valve or hoses, if it does not operate as specified.

ENGINE SENSORS & SWITCHES

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

Since many computer-controlled and monitored components set a diagnostic trouble code if they malfunction, testing procedures are covered in appropriate SELF-DIAGNOSTICS article.

A/C HIGH PRESSURE SWITCH

To test A/C high pressure switch, see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.

AUTOMATIC SPEED CONTROL INDICATOR

To test automatic speed control indicator, see appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.

BRAKE SWITCH

To test ACSD brake switch, see appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.

CAMSHAFT POSITION SENSOR

To test camshaft position sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

CRANKSHAFT POSITION SENSOR

To test crankshaft position sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

See EMISSION SYSTEMS & SUB-SYSTEMS .

ENGINE COOLANT TEMPERATURE SENSOR

To test engine coolant temperature sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

FRONT HEATED OXYGEN SENSOR

To test front HO2S, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

FUEL LEVEL SENSOR

To test fuel level sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

To test fuel tank temperature sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (ALTIMA & SENTRA 2.5L)»(ref-135812-S13133599062002110100000) table. If start signal displays as specified, go to step 8. If start signal does not display as specified, go to step 6. CHECKING START SIGNAL (ALTIMA & SENTRA 2.5L) Condition Start Signal Ignition Switch ON OFF Ignition Switch OFF ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 41 (Black/Yellow wire) while cranking engine. (Scheme 134) Battery voltage should exist when ignition switch is in START position. Voltage should be zero volts when ignition switch is in any other position except START. If voltage is as specified, go to step 8. If voltage is not as specified, go to next step.
  4. Turn ignition switch to OFF position, then to START position. If starter motor operates, go to next step. If starter motor does not operate, repair starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
  5. Turn ignition switch off. Check fuse block fuse No. 9 (10-amp). If fuse is okay, go to next step. If fuse is blown, replace and retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132)or (Scheme 133). Check continuity between ECM harness connector terminal No. 41 (Brown/White wire in Altima; Black/Yellow wire in Sentra) and fuse block through to battery. (Scheme 134)and «WIRING DIAGRAMS»(ref-135817) article. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  7. For Altima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M71 and F59. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors E30 and M3. Check for open or short in Green wire between ignition switch and fuse block. Check for open or short in Brown/White wire between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system. For Sentra, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors E103 and M2. Check for open or short in White/Red wire between ignition switch and fuse block. Check for open or short in Black/Yellow wire between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Altima (3.5L)

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (ALTIMA 3.5L)»(ref-135812-S05723346162002110400000) table. If start signal displays as specified, go to step 8. If start signal does not display as specified, go to step 4. CHECKING START SIGNAL (ALTIMA 3.5L) Condition Start Signal Ignition Switch ON OFF Ignition Switch START ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 42 (Brown/White wire) while cranking engine. (Scheme 134) Battery voltage should exist when ignition switch is in START position. Voltage should be zero volts when ignition switch is in any other position except START. If voltage is as specified, go to step 8. If voltage is not as specified, go to next step.
  4. Turn ignition switch to OFF position, then to START position. If starter motor operates, go to next step. If starter motor does not operate, repair starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
  5. Turn ignition switch off. Disconnect fuse block fuse No. 9 (10-amp). If fuse is okay, go to next step. If fuse is blown, replace and retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132)or (Scheme 133). Disconnect ignition switch harness connector. Check continuity in Brown/White wire between ECM harness connector terminal No. 42 and ignition switch harness connector terminal "R". (Scheme 134)and «WIRING DIAGRAMS»(ref-135817) article. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M71 and F59. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors E30 and M3. Check for open or short in Black/Yellow wire between ignition switch and fuse block. Check for open or short in Brown/White wire between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Frontier & Xterra

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (FRONTIER & XTERRA)»(ref-135812-S33279296492002110600000) table. If start signal displays as specified, go to step 7. If start signal does not display as specified, go to step 4. CHECKING START SIGNAL (FRONTIER & XTERRA) Condition Start Signal Ignition Switch ON OFF Ignition Switch START ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 20 (Blue/Orange wire). (Scheme 145)and (Scheme 146). Turn ignition switch to START position. Battery voltage should exist. With ignition switch in any other position, about zero volts should exist. If voltage is as specified, go to step 7. If voltage is not as specified, go to next step.
  4. Check fuse block fuse No. 7 (7.5-amp). Fuse block is located under left side of instrument panel. Replace fuse, if necessary. If fuse is okay, go to next step.
  5. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 145) Remove fuel block fuse No. 7. Check continuity between ECM harness connector terminal No. 20 (Blue/Orange wire) and fuse No. 7 socket cavity. Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  6. On 2.4L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E43 and M65. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M59 and F27. Check for open or short in Brown/White wire between ignition coil and ignition switch. On 3.3L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M81 and F36. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M26. Check for open or short in Brown/White wire between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system.
  7. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

I35 & Maxima

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (I35 & MAXIMA)»(ref-135812-S22708221002002110500000) table. If start signal displays as specified, go to step 8. If start signal does not display as specified, go to step 4. CHECKING START SIGNAL (I35 & MAXIMA) Condition Start Signal Ignition Switch ON OFF Ignition Switch START ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 42 (Brown/White wire) while cranking engine. (Scheme 134) Battery voltage should exist when ignition switch is in START position. Voltage should be zero volts when ignition switch is in any other position except START. If voltage is as specified, go to step 8. If voltage is not as specified, go to next step.
  4. Turn ignition switch to OFF position, then to START position. If starter motor operates, go to next step. If starter motor does not operate, repair starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
  5. Check fuse block fuse No. 21 (10-amp). Fuse block is located under left side of instrument panel. If fuse is blown, replace as necessary fuse. If fuse is okay, go to next step.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 141) Disconnect ignition switch 6-pin harness connector. Check continuity of Red/Black wire between ECM harness connector terminal No. 42 and ignition switch including fuse block fuse No. 26. (Scheme 134)and (Scheme 158). Continuity should exist. Also, check circuits for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F68 and M161. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M17 and E83. Check for open or short in Black/White wire between ignition switch and ECM. If problem is found, repair as necessary. After repair, retest system.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 158

Scheme 158
Scheme 158

Pathfinder & QX4

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (PATHFINDER & QX4)»(ref-135812-S18207732572002110400000) table. If start signal displays as specified, go to step 8. If start signal does not display as specified, go to step 4. CHECKING START SIGNAL (PATHFINDER & QX4) Condition Start Signal Ignition Switch ON OFF Ignition Switch START ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 42 (Black/Yellow wire) while cranking engine. (Scheme 134) Battery voltage should exist when ignition switch is in START position. Voltage should be zero volts when ignition switch is in any other position except START. If voltage is as specified, go to step 8. If voltage is not as specified, go to next step.
  4. Turn ignition switch to OFF position, then to START position. If starter motor operates, go to next step. If starter motor does not operate, repair starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
  5. Check fuse block fuse No. 26 (7.5-amp). Fuse block is located under left side of instrument panel. If fuse is blown, replace as necessary fuse. If fuse is okay, go to next step.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Disconnect ignition switch 6-pin harness connector. Check continuity of Red/Black wire between ECM harness connector terminal No. 42 and ignition switch harness connector including fuse block fuse No. 26. (Scheme 134)and (Scheme 158). Also, check circuits for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M32 and F23. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M10 and E3. Check for open or short in Red/Black wire between ignition switch and fuse block. Check for open or short in Black/Yellow wire between ECM and fuse block. If problem is found, repair as necessary. After repair, retest system.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Quest

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (QUEST)»(ref-135812-S24642427912002110500000) table. If start signal displays as specified, go to step 8. If start signal does not display as specified, go to step 4. CHECKING START SIGNAL (QUEST) Condition Start Signal Ignition Switch ON OFF Ignition Switch START ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 20 (Blue/Black wire) while cranking engine. (Scheme 146)and (Scheme 151). Battery voltage should exist when ignition switch is in START position. Voltage should be zero volts when ignition switch is in any other position except START. If voltage is as specified, go to step 8. If voltage is not as specified, go to next step.
  4. Turn ignition switch to OFF position, then to START position. If starter motor operates, go to next step. If starter motor does not operate, repair starting system. See appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
  5. Check fuse No. 12 (7.5-amp) located in fuse block. Fuse block is located under left side of instrument panel. If fuse is blown replace as necessary. If fuse is okay, go to next step.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 146) Check continuity of Blue/Black wire between ECM harness connector terminal No. 20 and fuse No. 12. (Scheme 151)and «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M42 and F104. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in Blue/Black wire between ECM and fuse. If problem is found, repair as necessary. After repair, retest system.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Sentra (1.8L)

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe START SIGNAL under following conditions. See «CHECKING START SIGNAL (SENTRA 1.8L)»(ref-135812-S27808698072002103000000) table. If start signal displays as specified, go to step 5. If start signal does not display as specified, go to step 4. CHECKING START SIGNAL (SENTRA 1.8L) Condition Start Signal Ignition Switch ON OFF Ignition Switch OFF ON
  3. Backprobing at ECM, measure voltage between ground and ECM terminal No. 41 (Black/Yellow wire) while cranking engine. (Scheme 146)and (Scheme 151). Battery voltage should exist when ignition switch is in START position. Voltage should be zero volts when ignition switch is in any other position except START. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5.
  4. Check following: Check for poor, loose, corrode or damaged terminal connections in in-line harness connectors M58 and F26. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 21 (10-amp). Fuse block is located under left side of instrument panel. Replace fuse, if necessary. Check for open or short in Black/Yellow wire between ECM harness connector terminal No. 41 and fuse No. 21 cavity in fuse block. If problem is found, repair as necessary. After repair, repeat steps 2 or 3 as needed. If no problem is found, go to next step.
  5. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

INTAKE AIR TEMPERATURE SENSOR

To test intake air temperature sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

KNOCK SENSOR

To test knock sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

MASS AIRFLOW SENSOR

To test mass airflow sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

POWER STEERING PRESSURE SWITCH

Turn ignition off. Disconnect power steering pressure switch harness connector. For locations (Scheme 159)- (Scheme 166). Start engine. Check continuity between switch terminals. If switch has only one terminal, check continuity between ground and switch terminal. Continuity should exist when steering wheel is being turned. Continuity should not exist when steering wheel is not being turned. Replace switch, if continuity is not as specified.

Scheme 159

Scheme 159: POWER STEERING PRESSURE SWITCH
Scheme 159: POWER STEERING PRESSURE SWITCH

Scheme 160

Scheme 160
Scheme 160

Scheme 161

Scheme 161
Scheme 161

Scheme 162

Scheme 162
Scheme 162

Scheme 163

Scheme 163
Scheme 163

Scheme 164

Scheme 164
Scheme 164

Scheme 165

Scheme 165
Scheme 165

Scheme 166

Scheme 166
Scheme 166

Altima

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe PW/ST SIGNAL in specified conditions. See «CHECKING POWER STEERING SWITCH FUNCTION (ALTIMA)»(ref-135812-S26482280922002110100000) table. If PW/ST SIGNAL is as specified, go to step 7. If signal is not as specified, go to step 4. CHECKING POWER STEERING SWITCH FUNCTION (ALTIMA) Condition PW/ST Signal Steering In Neutral Position OFF Steering Wheel Turned ON
  3. Start engine. Backprobing at ECM, measure voltage between ground and ECM terminal No. 46 (Green wire). (Scheme 133)and (Scheme 134). When steering wheel is being turned quickly, voltage should be about zero volts. When steering wheel is in straight ahead position, voltage should be about 5 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Disconnect power steering pressure switch harness connector. (Scheme 159) Check continuity of Green wire between power steering pressure switch harness connector and ECM harness connector terminal No. 46. See «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  5. Check for open or short in circuit between power steering pressure switch and ECM. If problem is found, repair as necessary. After repair, retest system.
  6. Check power steering pressure switch. See «POWER STEERING PRESSURE SWITCH»(ref-135812-S34544161632002022500000). If problem is found, replace switch. If switch is okay, go to next step.
  7. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe PW/ST SIGNAL in specified conditions. See «CHECKING POWER STEERING SWITCH FUNCTION (FRONTIER & XTERRA)»(ref-135812-S13768870212002110600000) table. If PW/ST SIGNAL is as specified, go to step 7. If signal is not as specified, go to step 4. CHECKING POWER STEERING SWITCH FUNCTION (FRONTIER & XTERRA) Condition PW/ST Signal Steering In Neutral Position OFF Steering Wheel Turned ON
  3. Start engine. Backprobing at ECM, measure voltage between ground and ECM terminal No. 39 (Gray/Red wire). (Scheme 145)and (Scheme 146). When steering wheel is being turned quickly, voltage should be about zero volts. When steering wheel is not being turned quickly, voltage should be about 5 volts. If voltage is as specified, go to step 7. If voltage is not as specified, go to next step.
  4. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 145) Check continuity of Gray/Red wire between power steering pressure switch harness connector terminal No. 1 and ECM harness connector terminal No. 39. (Scheme 146) Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 6.
  5. Check for open or short in Gray/Red wire between power steering pressure switch and ECM. If problem is found, repair as necessary. After repair, retest system.
  6. Check power steering pressure switch. See «POWER STEERING PRESSURE SWITCH»(ref-135812-S34544161632002022500000). If problem is found, repair as necessary. After repair, retest system.
  7. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

On I35 and Maxima to test power steering pressure switch, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - I35 & MAXIMA article.

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II in DATA MONITOR mode, observe PW/ST SIGNAL in specified conditions. See «CHECKING POWER STEERING SWITCH FUNCTION (PATHFINDER & QX4)»(ref-135812-S05765046142002110400000) table. If PW/ST SIGNAL is as specified, go to step 8. If signal is not as specified, go to step 4. CHECKING POWER STEERING SWITCH FUNCTION (PATHFINDER & QX4) Condition PW/ST Signal Steering In Neutral Position OFF Steering Wheel Turned ON
  3. Start engine. Backprobing at ECM, measure voltage between ground and ECM terminal No. 47 (Red/Black wire). (Scheme 134)and (Scheme 142). With steering wheel fully turned, voltage should be about zero volts. When steering wheel is not being turned, voltage should be about 5 volts. If voltage is as specified, go to step 8. If voltage is not as specified, go to next step.
  4. Turn ignition off. Disconnect power steering pressure switch harness connector. (Scheme 163) Check continuity between ground and power steering pressure switch harness connector terminal No. 2 (Black wire). Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair as necessary. If no problem is found, go to next step.
  5. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Check continuity of Red/Black wire between power steering pressure switch harness connector terminal No. 1 and ECM harness connector terminal No. 47. (Scheme 134) Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  6. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F23 and M32. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E48 and E102. Check for open or short in Red/Black wire between power steering oil pressure switch and ECM.
  7. Check power steering pressure switch. See «POWER STEERING PRESSURE SWITCH»(ref-135812-S34544161632002022500000). If problem is found, replace as necessary. If power steering pressure switch is okay, go to next step.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Using CONSULT-II from DATA MONITOR mode, observe PW/ST SIGNAL in specified conditions. See «CHECKING POWER STEERING SWITCH FUNCTION (QUEST)»(ref-135812-S02402786522002110500000) table. If PW/ST SIGNAL is as specified, go to step 6. If signal is not as specified, go to step 4. CHECKING POWER STEERING SWITCH FUNCTION (QUEST) Condition PW/ST Signal Steering In Neutral Position OFF Steering Wheel Turned ON
  3. Start engine. Backprobing at ECM, measure voltage between ground and ECM terminal No. 39 (Pink wire). (Scheme 146)and (Scheme 151). With steering wheel fully turned, voltage should be about zero volts. When steering wheel is not being turned, voltage should be about 5 volts. If voltage is as specified, go to step 6. If voltage is not as specified, go to next step.
  4. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 145) Disconnect power steering pressure switch harness connector. For switch location (Scheme 164) Check continuity of Pink wire between power steering pressure switch harness connector and ECM harness connector terminal No. 39. (Scheme 134) Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. After repair, retest system. If no problem is found, go to next step.
  5. Check power steering pressure switch. See «POWER STEERING PRESSURE SWITCH»(ref-135812-S34544161632002022500000). If problem is found, repair circuit as necessary. After repair, retest system. If no problem is found, go to next step.
  6. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Sentra

  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Start engine. Using CONSULT-II DATA MONITOR mode, observe PW/ST SIGNAL parameter. With steering wheel in neutral position PW/ST SIGNAL parameter should display OFF. When steering wheel is turned parameter should display ON. If parameter displays as specified, go to step 7. If parameter does not display as specified, go to step 4.
  3. Start engine. Backprobing at ECM, measure voltage between ground and ECM terminal No. 46 (Purple wire Sentra 1.8L; Green wire Sentra 2.5L). (Scheme 132)and (Scheme 134). When steering wheel is quickly turned, voltage should be about zero volts. When steering wheel is in neutral position, voltage should be about 5 volts. If voltage is as specified, go to step 7. If voltage is not as specified, go to next step.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Check continuity of Purple wire on Sentra 1.8L or Green wire on Sentra 2.5L between ECM harness connector terminal No. 46 and power steering switch harness connector terminal No. 1. (Scheme 134) Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  5. Check for open or short in Purple wire on Sentra 1.8L or Green wire on Sentra 2.5L between ECM and power steering switch. If problem is found, repair as necessary. After repair, repeat step 2 or 3 as needed. If no problem is found, go to next step.
  6. Check power steering pressure switch. See «POWER STEERING PRESSURE SWITCH»(ref-135812-S34544161632002022500000). Replace, if necessary. If power steering pressure switch is okay, go to next step.
  7. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

REAR HEATED OXYGEN SENSOR

To test rear HO2S, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

REFRIGERANT PRESSURE SENSOR

To test refrigerant pressure sensor, see appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.

THROTTLE POSITION SENSOR

To test throttle position sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

VEHICLE SPEED SENSOR

To test vehicle speed sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

FUEL SYSTEM

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

Relieving Fuel Pressure

Remove fuel pump fuse. Start engine and allow engine to run until it stalls. Crank engine an additional 2-3 times to ensure all pressure has dissipated.

Fuel Pressure

For basic fuel pressure procedures and specifications, see FUEL PRESSURE under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article.

Fuel Pressure Regulator

  1. Relieve fuel pressure from system. See «RELIEVING FUEL PRESSURE»(ref-135812-S14775277762002022500000) . Connect fuel pressure gauge in line between fuel filter and fuel rail. Remove vacuum hose from fuel pressure regulator, and plug hose. Connect hand-held vacuum pump to pressure regulator. Start engine and let idle.
  2. Gradually apply vacuum to regulator. Fuel pressure should decrease as vacuum increases. Compare values to «CHECKING FUEL PRESSURE»(ref-135504-S03329302502002022200000) in BASIC DIAGNOSTIC PROCEDURES article. If results are not as specified, replace fuel pressure regulator.

Fuel Pump

Disconnect fuel pump harness connector. For location, see FUEL PUMP HARNESS CONNECTOR LOCATIONS table. On Frontier 2.4L, measure resistance between fuel pump connector terminals No. 5 and 6. (Scheme 167) On I35, Maxima and Sentra, measure resistance between fuel pump connector terminals No. 1 and 3. (Scheme 168) On Quest, measure resistance between fuel pump connector terminals No. 2 and 3. (Scheme 169) On all other models, measure resistance between fuel pump 2-pin connector terminals. On all models, resistance should be 0.2-5.0 ohms at 77°F (25°C). Replace fuel pump, if resistance is not as specified.

ApplicationLocation
Altima, I35, Maxima, Pathfinder, QX4 & SentraUnder Rear Seat
Frontier & XterraTop Of Fuel Tank
QuestBehind Fuel Tank

FUEL PUMP HARNESS CONNECTOR LOCATIONS

Scheme 167

Scheme 167
Scheme 167

Scheme 168

Scheme 168
Scheme 168

Scheme 169

Scheme 169
Scheme 169

Fuel Pump Relay

See RELAYS under RELAYS & SOLENOIDS.

Fuel System Condenser

Turn ignition off. Disconnect 2-pin harness connector. Check resistance between condenser + and - pins. Resistance should be 1 m/ohms or more @ 77°F (25°C).

Inertia Fuel Shutoff Switch

Disconnect inertia fuel shut-off switch 3-pin harness connector. (Scheme 170) Measure continuity between inertia fuel shut-off switch harness connector terminals No. 2 (Black wire) and No. 3 (Black/White wire). When switch is open (tripped) continuity should not exist. When switch is closed (set) continuity should exist. If continuity is as specified, inertia switch is okay. If continuity is not as specified, replace switch.

Scheme 170

Scheme 170: Inertia Fuel Shutoff Switch
Scheme 170: Inertia Fuel Shutoff Switch

Fuel Pump Control System (Altima)

  1. Turn ignition on. Pinch fuel hose with fingers. Pulsation should be felt on fuel hose for 5 seconds after ignition is turned on. If pulsation is felt, system is okay. If pulsation is not felt, go to next step.
  2. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 29 (Black/Orange wire). (Scheme 134) If battery voltage does not exist, go to next step. If battery volage exists, go to step 5.
  3. Turn ignition off. Disconnect Intelligent Power Distribution Module (IPDM) 12-pin harness connector E122. IPDM is located at right front corner of engine compartment. Turn ignition on. Measure voltage between ground and IPDM harness connector terminal No. 20 (Black/Orange wire). (Scheme 144) If battery voltage exists, go to next step. If battery voltage does not exist, go to step 13.
  4. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E19 and F33. Check for open or short in circuits between IPDM and ECM. If problem is found, repair as necessary. After repair, retest system.
  5. Turn ignition off. Disconnect condenser 2-pin harness connector. Condenser is located under rear seat bottom. Measure voltage between ground and condenser + terminal. See «WIRING DIAGRAMS»(ref-135817) article. Turn ignition on. Battery voltage should exist for about one second after ignition is turned on. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9.
  6. Turn ignition off. Check IPDM fuse No. 32 (15-amp). If fuse is okay, go to next step. If fuse is blown, replace fuse and retest system.
  7. Turn ignition off. Disconnect Intelligent Power Distribution Module (IPDM) 12-pin harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of Black/Yellow wire between IPDM harness connector terminal No. 23 and fuel condenser + terminal. (Scheme 144) Continuity should exist. Also, check for open or short in circuits between IPDM and condenser If problem is found, go to next step. If no problem is found, go to step 13.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E130 and E27. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E33 and B3. Check for open or short in circuits between IPDM and condenser. If problem is found, repair as necessary. After repair, retest system.
  9. Check continuity in Black wire between ground and condenser - terminal. Continuity should exist. If no problem is found, go to next step. If problem is found, replace condenser. After repair, retest system.
  10. Check condenser. See «FUEL SYSTEM CONDENSER»(ref-135812-S25495920772002110100000). If no problem is found, go to next step. If problem is found, replace condenser. After repair, retest system.
  11. Turn ignition off. Access fuel level sensor unit harness connector by removing access cover located under rear seat. Disconnect fuel level sensor unit 5-pin harness connector. Check continuity in Black/Yellow wire between in-line harness connector B3 terminal No. 4 and fuel level sensor unit harness + connector. See «WIRING DIAGRAMS»(ref-135817) article. Check continuity in Black wire between ground and fuel level sensor unit harness - connector. Also, check circuits for short to ground or short to voltage. If no problem is found, go to next step. If problem is found, repair or replace as necessary. After repair, retest system.
  12. Check fuel pump. See «FUEL PUMP»(ref-135812-S19677628812002022500000). If no problem is found, go to next step. If problem is found, repair or replace as necessary. After repair, retest system.
  13. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article. If problem is found, repair or replace as necessary. If no problem is found, replace IPDM.

Fuel Pump Control System (Frontier & Xterra)

  1. Turn ignition on. Pinch fuel feed hose with fingers. Pulsation should be felt on fuel hose for 5 seconds after ignition is turned on. If pulsation is felt, go to step 11. If pulsation is not felt, go to next step.
  2. Turn ignition off. Disconnect fuel pump relay harness connector. Fuel pump relay is located behind left side of instrument panel, above parking brake lever. (Scheme 171) Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 2 and 5 (Black/White wires). (Scheme 147) If battery voltage does not exist at both terminals, go to next step. On Frontier 3.3L, Xterra 2.4L and Xterra 3.3L if battery voltage exists at both terminals, leave fuel pump relay disconnected and go to step 4. On Frontier 2.4L if battery voltage exists at both terminals, leave fuel pump relay disconnected and go to step 5.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M31. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 1 (15-amp). Check for open or short in circuits between fuse and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  4. On Frontier 3.3L, Xterra 3.3L or Xterra 2.4L perform following procedure: Turn ignition off. Disconnect fuel pump 2-pin harness connector. Fuel pump harness connector is located on top of fuel tank and can be accessed under vehicle. Check continuity of Black wire between ground and fuel pump harness connector terminal No. 2. See «WIRING DIAGRAMS»(ref-135817) article. Check continuity of White/Blue wire between fuel pump relay harness connector terminal No. 3 and fuel pump harness connector terminal No. 1. Continuity should exist at each measurement. Also, check circuit for short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  5. On Frontier 2.4L perform following procedure: Turn ignition off. Disconnect fuel pump and level sensor 6-pin harness connector. Fuel pump harness connector is located on top of fuel tank and can be accessed under vehicle. Check continuity of Black wire between ground and fuel pump harness connector terminal No. 6. (Scheme 167) Check continuity of White/Blue wire between fuel pump relay harness connector terminal No. 3 and fuel pump harness connector terminal No. 5. Continuity should exist at each measurement. Also, check circuit for short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  6. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors B101 and M67. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between body ground and fuel pump. Check for open or short in circuits between fuel pump and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  7. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 145) Check continuity of White/Red wire between ECM harness connector terminal No. 11 and fuel pump relay harness connector terminal No. 1. (Scheme 146)and (Scheme 147). Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 9.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F36 and M81. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between fuel pump and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  9. Connect fuel pump relay and any disconnected harness connectors. Turn ignition on. Using CONSULT-II in ACTIVE TEST mode, turn fuel pump On and Off. Fuel pump relay should click audibly. If fuel pump relay clicks as specified, go to next step. If fuel pump relay does not click as specified, replace relay. If CONSULT-II is not available, perform following test. Working with fuel pump relay, apply battery voltage and ground to fuel pump relay terminals No. 1 and 2. (Scheme 147) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  10. Check fuel pump. See «FUEL PUMP»(ref-135812-S19677628812002022500000). If problem is found, repair or replace fuel pump as necessary. If fuel pump is okay, go to next step.
  11. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article

Scheme 171

Scheme 171
Scheme 171

Fuel Pump Control System (I35 & Maxima)

  1. Turn ignition on. Pinch fuel hose with fingers. Pulsation should be felt on fuel hose for one second after ignition is turned on. If pulsation is felt, system is okay. If pulsation is not felt, go to next step.
  2. Turn ignition off. Disconnect fuel pump relay harness connector. Fuel pump relay is located behind left kick panel. (Scheme 172) Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 1 (Black/Red wire) and No. 5 (Black/White wire). (Scheme 147) If battery voltage does not exist at both terminals, go to next step. If battery voltage exists at both terminals, go to step 4.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector B5. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 17 (10-amp). Check fuse block fuse No. 29 (15-amp). Check for open or short in circuits between fuse and fuel pump relay.
  4. Turn ignition off. Access fuel level sensor unit harness connector by removing cover under rear seat. Disconnect fuel system condenser 2-pin harness connector. Condenser is located under rear seat near fuel pump access. Check continuity in Black/Yellow wire between fuel pump relay harness connector terminal No. 3 and condenser harness connector terminal No. 1. See «WIRING DIAGRAMS»(ref-135817) article. Check continuity in Black wire between ground and condenser harness connector terminal No. 2. Continuity should exist at both measurements. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 6.
  5. Check following: Check for open or short in circuits between fuel pump relay and condenser. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between condenser and body ground. If problem is found, repair as necessary. After repair, retest system.
  6. Check condenser. See «FUEL SYSTEM CONDENSER»(ref-135812-S25495920772002110100000). If no problem is found, go to next step. If problem is found, replace condenser. After repair, retest system.
  7. Turn ignition off. Disconnect fuel pump harness connector located under access cover, under rear seat. Check continuity between ground and fuel pump harness connector terminal No. 3 (Black wire). (Scheme 173) Continuity should exist. Also, check circuit for short to voltage. If problem is found, go to next step. If no problem is found, go to step 9.
  8. Check following: Check for open or short in Black/Yellow wire between fuel pump relay and fuel pump. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in Black wire between body ground and fuel pump. If problem is found, repair as necessary. After repair, retest system.
  9. Turn ignition off. Disconnect ECM 116-pin harness connector. (Scheme 141) Check continuity of Black/Pink wire between ECM harness connector terminal No. 28 and fuel pump relay harness connector terminal No. 2. (Scheme 134)and (Scheme 147). Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 11.
  10. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors B3 and M6. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F49 and M81. Check for open or short in Black/Pink wire between ECM and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  11. Connect fuel pump relay and any disconnected harness connectors. Turn ignition on. Using CONSULT-II in ACTIVE TEST mode, turn fuel pump On and Off. Fuel pump relays should click audibly. If fuel pump relay clicks as specified, go to next step. If fuel pump relay does not click as specified, replace relay. If CONSULT-II is not available, perform following test. Working with fuel pump relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 147) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  12. Check fuel pump. See «FUEL PUMP»(ref-135812-S19677628812002022500000). Replace, if necessary. If fuel pump is okay, go to next step.
  13. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article

Scheme 172

Scheme 172
Scheme 172

Scheme 173

Scheme 173
Scheme 173

Fuel Pump Control System (Pathfinder & QX4)

  1. Turn ignition on. Pinch fuel hose with fingers. Pulsation should be felt on fuel hose for one second after ignition is turned on. If pulsation is felt, system is okay. If pulsation is not felt, go to next step.
  2. Turn ignition off. Remove fuel pump relays No. 1 and 2. (Scheme 150)and (Scheme 174). Turn ignition on. Measure voltage between ground and fuel pump relays No. 1 and 2 harness connector terminal No. 1 (Black/Yellow wires). (Scheme 175) If battery voltage does not exist, go to next step. If battery voltage exists, leave relays disconnected and go to step 4.
  3. Check following: Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M10. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 17 (15-amp). Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M1 and E1. Check for open or short in circuits between fuse and fuel pump relays No. 1 and 2. If problem is found, repair as necessary. After repair, retest system.
  4. Measure voltage between ground and fuel pump relay No. 1 harness connector terminal No. 3 (Black/Red wire). If battery voltage does not exist, leave relays disconnected and go to next step. If battery voltage exists, leave relays disconnected and go to step 8.
  5. Turn ignition off. Check continuity of Black/Red wire between fuel pump relay No. 2 harness connector terminal No. 5 and fuel pump relay No. 1 harness connector terminal No. 3. Continuity should exist. Also, check circuit for short to ground and short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition on. Measure voltage between ground and fuel pump relay No. 2 harness connector terminals No. 1 (Black/Yellow wire) and No. 3 (Black/White wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 8.
  7. Check following: Check fusible link and relay box fuse No. 66 (15-amp). Check for open or short in Black/White wire between fuse and fuel pump relay No. 2. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  8. Turn ignition off. Check continuity in Black wire between ground and fuel pump relay No. 2 harness connector terminal No. 1. (Scheme 175) Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair as necessary. If no problem is found, go to next step.
  9. Turn ignition off. Disconnect fuel pump harness connector located under access cover, under rear seat. Check continuity between ground and fuel pump harness connector terminal No. 2 (Black wire). Continuity should exist. Check continuity of White/Blue wire between fuel pump harness connector terminal No. 1 and fuel pump relay No. 1 harness connector terminal No. 5. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 11.
  10. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M1 and E1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M2 and B2. Check for open or short in circuits between fuel pump and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  11. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Check continuity of Purple/Blue wire between ECM harness connector terminal No. 28 and fuel pump relay No. 1 harness connector terminal No. 2. (Scheme 134)and (Scheme 175). Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, and CONSULT-II is available, go to step 13. If no problem is found, and CONSULT-II is not available, go to step 14.
  12. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M1 and E1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M32 and F23. Check for open or short in circuits between ECM and fuel pump relay No. 1. If problem is found, repair as necessary. After repair, retest system.
  13. Connect fuel pump relays and any other disconnected harness connectors. Turn ignition on. Using CONSULT-II in ACTIVE TEST mode, turn fuel pump relays No. 1 and 2 On and Off. Fuel pump relays should click audibly. If fuel pump relays click as specified, go to step 15. If fuel pump relays do not click as specified, replace relay(s).
  14. Working first with fuel pump relay No. 1, apply battery voltage and ground to fuel pump relay terminals No. 1 and 2. (Scheme 175) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. Repeat test with fuel pump relay No. 2. Replace suspect relay, if test values are not as specified. If relay tests okay, go to next step.
  15. Check fuel pump. See «FUEL PUMP»(ref-135812-S19677628812002022500000). Replace, if necessary. If fuel pump is okay, go to next step.
  16. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 174

Scheme 174
Scheme 174

Scheme 175

Scheme 175
Scheme 175

Fuel Pump Control System (Quest)

  1. Check inertia fuel shutoff switch located behind left kick panel. (Scheme 170) If switch has been triggered, push reset button. If switch has not been triggered, go to next step.
  2. Turn ignition on. Pinch fuel hose with fingers. Pulsation should be felt on fuel hose for 5 seconds after ignition is turned on. If pulsation is felt, go to step 12. If pulsation is not felt, go to next step.
  3. Turn ignition off. Remove fuel pump relay. (Scheme 176) Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 1 and 3 (Black/Red wires). (Scheme 147) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 5.
  4. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M1 and E101. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in joint connector-4. Check fuse block fuse No. 29 (10-amp). Check for open or short in circuits between fuse and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  5. Turn ignition off. Disconnect fuel pump harness connector located behind fuel tank. Check continuity in Light Green/Red wire between fuel pump harness connector terminal No. 2 and fuel pump relay harness connector terminal No. 5. (Scheme 147)and (Scheme 169). Check continuity in Black/White wire between ground and fuel pump harness connector terminal No. 3. Continuity should exist. Also, check circuit for short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  6. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M1 and E101. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M124 and B201. Check for open or short in circuits between body ground and fuel pump. Check for open or short in circuits between fuel pump and fuel pump relay. Check inertia fuel shut-off switch. See «INERTIA FUEL SHUTOFF SWITCH»(ref-135812-S33871246232002110500000). If problem is found, repair as necessary. After repair, retest system.
  7. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 151) Check continuity of Blue/Red wire between ECM harness connector terminal No. 11 and fuel pump relay harness connector terminal No. 2. (Scheme 146)and (Scheme 147). Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. In no problem is found and CONSULT-II is available, go to step 9. In no problem is found and CONSULT-II is not available, go to step 10.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E53 and F2. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  9. Connect fuel pump relay and any disconnected harness connectors. Turn ignition on. Using CONSULT-II in ACTIVE TEST mode, turn fuel pump On and Off. Fuel pump relays should click audibly. If fuel pump relay clicks as specified, go to next step. If fuel pump relay does not click as specified, replace relay.
  10. Working with fuel pump relay, apply battery voltage and ground to fuel pump relay terminals No. 1 and 2. (Scheme 147) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  11. Check fuel pump. See «FUEL PUMP»(ref-135812-S19677628812002022500000). If problem is found, replace, if necessary. If fuel pump is okay, go to next step.
  12. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article

Scheme 176

Scheme 176
Scheme 176

Fuel Pump Control System (Sentra)

  1. Turn ignition on. Pinch supply fuel hose with fingers. Pulsation should be felt on fuel hose for 5 seconds after ignition is turned on. If pulsation is felt, system is okay. If pulsation is not felt, go to next step.
  2. Turn ignition off. Disconnect fuel pump relay harness connector. Fuel pump relay is located behind left kick panel. (Scheme 177) Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 1 (Black/Red wire). (Scheme 175) If battery voltage does not exist, go to next step. If battery voltage exists, leave harness connector disconnected and go to step 4.
  3. Check following: Check fuse block fuse No. 17 (10-amp). Check for open or short in Black/Red wire between fuel pump relay and fuse block. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  4. Measure voltage between ground and fuel pump relay terminal No. 5 (Black/White wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 9.
  5. Check following: Check fuse block fuse No. 29 (15-amp). Check for open or short in Black/White wire between fuel pump relay and fuse block. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect fuel pump harness connector located behind access cover, under rear seat. Check continuity between ground and fuel pump harness connector terminal No. 3 (Black wire). (Scheme 173)and (Scheme 175). Check continuity in Black/Yellow wire between fuel pump harness connector terminal No. 1 and fuel pump relay harness connector terminal No. 3. Continuity should exist at both measurements. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  7. Check following: Check for open or short in Black wire between ground and fuel pump. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in Black/Yellow wire between fuel pump and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  8. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Check continuity of Black/Pink wire between fuel pump relay harness connector terminal No. 2 and ECM harness connector terminal No. 20. (Scheme 134)and (Scheme 175). Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 10.
  9. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors B3 and M16. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. Check for open or short in circuits between ECM and fuel pump relay. If problem is found, repair as necessary. After repair, retest system.
  10. Working with fuel pump relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 175) When battery voltage is applied, continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. Replace relay, if test values are not as specified. If relay tests okay, go to next step.
  11. Check fuel pump. See «FUEL PUMP»(ref-135812-S19677628812002022500000). If problem is found, replace as necessary. If fuel pump is okay, go to next step.
  12. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 177

Scheme 177
Scheme 177

Fuel Injector

Turn ignition off. Disconnect fuel injector harness connector. Measure resistance between injector terminals. See FUEL INJECTOR RESISTANCE table for specification. Replace injector, if resistance is not as specified.

ApplicationSpecification
Altima (2.5L)7.3-9.9 Ohms @ 77°F (25°C)
Frontier & Xterra
2.4L7.3-9.9 Ohms @ 77°F (25°C)
3.3L10-14 Ohms @ 77°F (25°C)
Altima (3.5L), I35, Maxima, Pathfinder, QX4 & Sentra13.5-17.5 Ohms @ 68°F (20°C)
Quest10-14 Ohms @ 77°F (25°C)

FUEL INJECTOR RESISTANCE

Fuel Injector Circuits (Altima & Sentra 2.5L)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 8. If engined does not perform as specified, go to step 4.
  3. Start engine and listen to each fuel injector. If every injector clicks, system is okay. If any injector does not click, go to next step
  4. Turn ignition off. Disconnect suspect fuel injector 2-pin harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 2 (Pink wire). See «WIRING DIAGRAMS»(ref-135817) article. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. For Sentra, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E108 and M19. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E10 and F48. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F101. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M1. Check fuse block fuse No. 17 (10-amp). Check for open or short between suspect fuel injector and fuse. For Altima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F59 and M71. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F101. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M4. Check fuse block fuse No. 1 (10-amp). Check for open or short between suspect fuel injector and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. (Scheme 132)or (Scheme 133). Check continuity of specified wire between fuel injector harness connector terminal No. 2 and ECM. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (ALTIMA & SENTRA 2.5L)»(ref-135812-S17514729172002022500000) table. (Scheme 134) Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8. FUEL INJECTOR CIRCUIT IDENTIFICATION (ALTIMA & SENTRA 2.5L) Injector No. Wire Color At Injector Terminal No. 2 ECM Terminal No. Wire Color At ECM 1 White 101 Red/Black 2 Red/White 102 Yellow/Black 3 Green/Black 103 Green/Black 4 Red/Blue 104 Blue/Black
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F101. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect fuel injector and ECM.
  8. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace as necessary. If no problem is indicated at this time, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Fuel Injector Circuits (Altima 3.5L)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 9. If engine does not perform as specified, go to step 4.
  3. Start engine and listen to each fuel injector. If every injector clicks, go to step 9. If any injector does not click, go to next step
  4. Turn ignition off. Disconnect suspect fuel injector 2-pin harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Red wire). See «WIRING DIAGRAMS»(ref-135817) article. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F59 and M71. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F44 and F101. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M4. Check fuse block fuse No. 1 (10-amp). Check for open or short between suspect fuel injector and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. (Scheme 133) Check continuity of specified wire between fuel injector harness connector terminal No. 2 and ECM. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (ALTIMA 3.5L)»(ref-135812-S17232110402002110400000) table. (Scheme 134) Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8. FUEL INJECTOR CIRCUIT IDENTIFICATION (ALTIMA 3.5L) Injector No. ECM Terminal No. Wire Color 1 1 Red/Black 2 2 Red/White 3 3 Red/Yellow 4 11 Red/Blue 5 12 Blue/White 6 13 Purple/Red
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F44 and F101. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect fuel injector and ECM.
  8. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace as necessary. If no problem is indicated at this time, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Fuel Injector Circuits (Frontier & Xterra)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 9. If engine does not perform as specified, go to step 4.
  3. Start engine. Listen to each fuel injector. If every injector clicks, go to step 9. If any injector does not click, go to next step.
  4. Turn ignition off. Disconnect suspect injector 2-pin harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Black/Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. For 2.4L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F27 and M59. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M26. Check fuse block fuse No. 3 (10-amp). Check for open or short between suspect fuel injector and fuse. For 3.3L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F27 and M59. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F37 and F101. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M26. Check fuse block fuse No. 3 (10-amp). Check for open or short between suspect fuel injector and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 145) Check continuity of specified wire between ECM harness connector and appropriate injector harness connector terminal No. 2. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (FRONTIER & XTERRA)»(ref-135812-S04834831082002022500000) table. (Scheme 146) Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8. FUEL INJECTOR CIRCUIT IDENTIFICATION (FRONTIER & XTERRA) Injector No. ECM Terminal No. Wire Color 1 102 White/Black 2 109 White/Blue 3 104 White/Red 4 111 White/Purple 5 (1) 106 White/Green 6 (1) 113 White (1) V6 only.
  7. For 2.4L, check for open or short in circuit between suspect injector and ECM. For 3.3L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F37 and F101. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F38 and F102. Check for open or short between suspect fuel injector and fuse. If problem is found, repair as necessary. After repair, retest system.
  8. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace as necessary. If no problem is found, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Fuel Injector Circuits (I35 & Maxima)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 10. If engine does not perform as specified, go to step 4.
  3. Start engine and listen to each fuel injector. If every injector clicks, go to step 10. If any injector does not click, go to next step
  4. Turn ignition off. On bank 1 disconnect fuel injector 2-pin harness connectors. On bank 2 disconnect fuel injector 8-pin sub-harness connector F58. Sub-harness connector F58 is located on left side of intake manifold. (Scheme 178) Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Red wire). See «WIRING DIAGRAMS»(ref-135817) article. Measure voltage between ground and fuel injector sub-harness connector terminal No. 5 (Red wire). (Scheme 179) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F68 and M161. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F58 and F197. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M19. Check fuse block fuse No. 17 (10-amp). Check for open or short between suspect fuel injector and fuse. Check for open or short between sub-harness connector terminal No. 5 and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 141) Check continuity between fuel injector harness connector terminal No. 2 and specified ECM or injector sub-harness connector terminal. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (I35 & MAXIMA)»(ref-135812-S39677133752002110500000) table. (Scheme 134)and (Scheme 179). Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, leave harness connectors disconnected and go to step 8. FUEL INJECTOR CIRCUIT IDENTIFICATION (I35 & MAXIMA) Injector No. ECM Terminal No. Injector Sub-Harness Terminal No. Wire Color 1..... 6 Red/Black 2 2..... Red/White 3..... 2 Red/Yellow 4 11..... Red/Blue 5..... 1 Blue/White 6 13..... Purple/Red
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F58 and F191. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between in-line harness connector F58 and ECM. Check for open or short between suspect fuel injector and ECM. If problem is found, repair as necessary. After repair, retest system.
  8. Disconnect bank 1 fuel injector 2-pin harness connectors. Check continuity between specified fuel injector harness connector terminal and injector sub-harness connector F197 terminal. See «CHECKING FUEL INJECTOR SUB-HARNESS CONNECTOR (I35 & MAXIMA)»(ref-135812-S08206829932002110500000) table. (Scheme 179) Continuity should exist. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system. CHECKING FUEL INJECTOR SUB-HARNESS CONNECTOR (I35 & MAXIMA) Fuel Injector No. Sub-Harness Connector Terminal Wire Color 1 6 Red/Black 3 2 Red/Yellow 5 1 Blue/White Power Supply 5 Red
  9. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace as necessary. If no problem is indicated at this time, go to next step.
  10. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 178

Scheme 178
Scheme 178

Scheme 179

Scheme 179
Scheme 179

Fuel Injector Circuits (Pathfinder & QX4)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 10. If engine does not perform as specified, go to step 4.
  3. Start engine and listen to each fuel injector. If every injector clicks, go to step 10. If any injector does not click, go to next step
  4. Turn ignition off. Disconnect suspect fuel injector 2-pin harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Red wire). See «WIRING DIAGRAMS»(ref-135817) article. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F22 and M33. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F5 and F100. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connector M10. Check fuse block fuse No. 21 (10-amp). Check for open or short between suspect fuel injector and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. (Scheme 142) Check continuity between fuel injector harness connector terminal No. 2 and specified ECM harness connector terminal. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (PATHFINDER & QX4)»(ref-135812-S27274409512002110400000) table. (Scheme 134) Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 9. FUEL INJECTOR CIRCUIT IDENTIFICATION (PATHFINDER & QX4) Injector No. ECM Terminal No. Wire Color 1 101 Red/Black 2 103 Red/White 3 105 Red/Yellow 4 107 Red/Blue 5 102 Blue/White 6 104 Purple/Red
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F5 and F100. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between in-line harness connector F5 and ECM. Check for open or short between in-line harness connector F100 and suspect fuel injector. If problem is found, repair as necessary. After repair, retest system.
  8. Disconnect 8-pin in-line harness connector F100. In-line harness connector is located along leftside of intake manifold. Disconnect all fuel injector 2-pin harness connectors. Check continuity between all fuel injector harness connector terminal No. 2 and specified in-line harness connector F100 terminals. See «CHECKING FUEL INJECTOR SUB-HARNESS CONNECTOR (PATHFINDER & QX4)»(ref-135812-S26824719502002110400000) table. (Scheme 179) Continuity should exist. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system. CHECKING FUEL INJECTOR SUB-HARNESS CONNECTOR (PATHFINDER & QX4) Sub-Harness Connector Terminal No. Wire Color Fuel Injector No. 1 Blue/White 5 2 Red/Yellow 3 3 Red/Blue 4 4 Red/White 2 5 Red Power Supply 6 Red/Black 1 7 Purple/Red 6
  9. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace as necessary. If no problem is indicated at this time, go to next step.
  10. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Fuel Injector Circuits (Quest)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 9. If engine does not perform as specified, go to step 4.
  3. Start engine. Listen to each fuel injector. If every injector clicks, go to step 9. If any injector does not click, go to next step.
  4. Turn ignition off. Disconnect suspect injector 2-pin harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 2 (Yellow wire). See «WIRING DIAGRAMS»(ref-135817) article. If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E53 and F2. Check for open or short between suspect fuel injector and battery. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 151) Check continuity of specified wire between ECM harness connector and injector harness connector terminal No. 1. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (QUEST)»(ref-135812-S11951746802002022500000) table. (Scheme 146) Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8. FUEL INJECTOR CIRCUIT IDENTIFICATION (QUEST) Injector No. ECM Terminal No. Wire Color 1 102 Green/Orange 2 109 Green 3 104 Green/Red 4 111 Yellow/Purple 5 106 Yellow/Green 6 113 Gray/Blue
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect fuel injector and ECM. If problem is found, repair as necessary. After repair, retest system.
  8. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace, if necessary. After repair, retest system. If no problem is found, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Fuel Injector Circuits (Sentra 1.8L)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step 9. If engined does not perform as specified, go to step 4.
  3. Start engine and listen to each fuel injector. If every injector clicks, system is okay. If any injector does not click, go to next step
  4. Turn ignition off. Disconnect suspect fuel injector harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Black/Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check fuse block fuse No. 17 (10-amp). Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M19 and E108. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E9 and F47. Check for open or short in Black/Red wire between suspect injector and fuse. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition switch off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Check continuity in specified circuits between injector harness connector terminal No. 2 and ECM. See «FUEL INJECTOR CIRCUIT IDENTIFICATION (SENTRA)»(ref-135812-S35443173262002022500000) table. (Scheme 134) Continuity should exist. Also, check harness for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 8. FUEL INJECTOR CIRCUIT IDENTIFICATION (SENTRA) Injector No. ECM Terminal No. Wire Color 1 101 Red/Black 2 103 Yellow/Black 3 105 Green/Black 4 107 Blue/Black
  7. Check for open or short in circuits between suspect injector and ECM. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. If no problem is found, go to next step.
  8. Check fuel injector. See «FUEL INJECTOR»(ref-135812-S04288376342002022500000). If problem is found, replace as necessary. See «FUEL SYSTEM»(ref-135816-S22759198932002022500000) in REMOVAL, OVERHAUL & INSTALLATION. If injector is okay, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

IDLE CONTROL SYSTEM

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

IDLE AIR CONTROL VALVE-AUXILIARY AIR CONTROL VALVE

To test idle air control valve-auxiliary air control valve, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

  1. Start engine and warm to normal operating temperature. Check idle speed. Idle speed should be 750-850 RPM (on 2.4L) or 700-800 RPM (on 3.3L) with transmission in Park or Neutral. If idle speed is as specified, go to next step. If idle speed is not as specified, adjust idle speed. See «THROTTLE POSITION SWITCH, IGNITION TIMING & IDLE SPEED»(ref-135501-S10594987612002022200000) in ON-VEHICLE ADJUSTMENTS article.
  2. Turn A/C and blower on, then recheck idle speed. Idle speed should now be 875 RPM or more (on 2.4L), or 850 RPM or more (on 3.3L). If idle speed is as specified, go to next step. If idle speed is not as specified, verify that A/C compressor functions normally. If A/C compressor functions normally, turn A/C off and go to next step. If A/C compressor does not function normally, repair A/C system as necessary. See appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  3. Turn ignition off. Disconnect Idle Air Control Valve-Fast Idle Control Device (IACV-FICD) solenoid valve 2-pin harness connector. (Scheme 180)or (Scheme 181). Start engine. Turn A/C and blower on. Measure voltage between ground and IACV-FICD solenoid valve harness connector terminal No. 2 (Green/Black wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 5.
  4. On 2.4L, check following: Check for open or short in Green/Black wire between IACV-FICD solenoid valve and in-line harness connector F27. See «WIRING DIAGRAMS»(ref-135817) article. On 3.3L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F38 and F102. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in Green/Black wire between IACV-FICD solenoid valve and in-line harness connector F27. If problem is found, repair as necessary. After repair, retest system.
  5. Turn ignition off. Check continuity between ground and IACV-FICD solenoid valve harness connector terminal No. 1 (Black/Red wire). Continuity should exist. Also, check circuit for short to voltage. If problem is found, go to next step. If no problem is found, go to step 8.
  6. Check continuity in Black/Yellow wire between IACV-FICD solenoid valve harness connector terminal No. 1 and Ambient Temperature (AT) sensor harness connector terminal No. 2. See «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist. If problem is found, go to next step. If no problem is found, go to step 8.
  7. On 2.4L, check following: Check for open or short in circuits between ground and IACV-FICD solenoid valve. See «WIRING DIAGRAMS»(ref-135817) article. On 3.3L, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F38 and F102. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F36 and M81. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M65 and E43. Check for open or short in diode F35. Check for open or short in circuits between ground and ambient temperature switch. Check for open or short in circuits between IACV-FICD solenoid valve and ambient temperature switch. If problem is found, repair as necessary. After repair, retest system.
  8. Check IACV-FICD solenoid valve. See «IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE SOLENOID VALVE»(ref-135812-S35366040262002022500000). If problem is found, replace IACV-FICD solenoid valve. If IACV-FICD solenoid valve is okay, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 180

Scheme 180
Scheme 180

Scheme 181

Scheme 181
Scheme 181
  1. Start engine and warm to normal operating temperature. Check idle speed. Idle speed should be 700-800 RPM with transmission in Park or Neutral. If idle speed is as specified, go to next step. If idle speed is not as specified, adjust idle speed. See «THROTTLE POSITION SWITCH, IGNITION TIMING & IDLE SPEED»(ref-135501-S10594987612002022200000) in ON-VEHICLE ADJUSTMENTS article.
  2. Turn A/C and blower on, then recheck idle speed. Idle speed should be 800 RPM or more. If idle speed is as specified, go to next step. If idle speed is not as specified, verify that A/C compressor functions normally. If A/C compressor functions normally, turn A/C off and go to next step. If A/C compressor does not function normally, repair A/C system as necessary. See appropriate MANUAL or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  3. Turn ignition off. Disconnect Idle Air Control Valve-Fast Idle Control Device (IACV-FICD) solenoid valve harness connector. For IACV-FICD location (Scheme 182) Start engine. Measure voltage between ground and IACV-FICD solenoid valve harness connector terminal No. 3 (Gray/Red wire). (Scheme 183) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 5.
  4. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E53 and F2. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F201. Check for open or short in Gray/Red wire between IACV-FICD solenoid valve and A/C relay. If problem is found, repair as necessary. After repair, retest system.
  5. Turn ignition off. Check continuity between ground and IACV-FICD solenoid valve harness connector terminal No. 4 (Black wire). Continuity should exist. Also, check circuit for short to voltage. If problem is found, go to next step. If no problem is found, go to step 7.
  6. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F12 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in Gray/Red wire between IACV-FICD solenoid valve and body ground. If problem is found, repair as necessary. After repair, retest system.
  7. Check IACV-FICD solenoid valve. See «IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE SOLENOID VALVE»(ref-135812-S35366040262002022500000). If problem is found, replace IACV-FICD solenoid valve. If IACV-FICD solenoid valve is okay, go to next step.
  8. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 182

Scheme 182
Scheme 182

Scheme 183

Scheme 183
Scheme 183

IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE SOLENOID VALVE

Remove IACV-FICD solenoid valve. See COMPONENT LOCATIONS. Using jumper wires, apply battery voltage to IACV-FICD solenoid terminals. On Quest (Scheme 184) On all models, IACV-FICD solenoid should click. Inspect IACV-FICD solenoid plunger for sticking. Also check for broken spring. Replace IACV-FICD solenoid, if operation is not as specified.

Scheme 184

Scheme 184: IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE SOLENOID VALVE
Scheme 184: IDLE AIR CONTROL VALVE-FAST IDLE CONTROL DEVICE SOLENOID VALVE

IGNITION SYSTEM

If engine cranks but does not run or immediately stalls, perform appropriate ENGINE CRANKS BUT WILL NOT RUN testing procedure under NO START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES article. Engine cranks but will not run diagnostic procedure will determine if problem is in the ignition or fuel systems. If any DTC are stored, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

IGNITION COIL (FRONTIER, XTERRA & QUEST)

Ignition coil is located in distributor. Turn ignition off. Disconnect distributor 2-pin harness connector (ignition coil connector). Remove distributor cap. For primary coil, measure resistance between distributor 2-pin connector terminals (component side). For secondary coil, measure resistance between distributor 2-pin connector terminal No. 7 and coil tower. (Scheme 185) See IGNITION COIL RESISTANCE (FRONTIER, XTERRA & QUEST) table. Replace distributor assembly, if resistance is not as specified.

ApplicationPrimarySecondary
Frontier & Xterra
2.4LLess Than 1 Ohm @ 77°F (25°C)7-13 K/Ohms @ 77°F (25°C)
3.3L.5-1.0 Ohm @ 77°F (25°C)About 12 K/Ohms @ 77°F (25°C)
Quest.5-1.0 Ohm @ 77°F (25°C)About 12 K/Ohms @ 77°F (25°C)

IGNITION COIL RESISTANCE (FRONTIER, XTERRA & QUEST)

Scheme 185

Scheme 185
Scheme 185

POWER TRANSISTOR

Power transistor is located in distributor. Turn ignition off. Disconnect distributor 2-pin and 6-pin harness connectors. Measure resistance between distributor 2-pin connector terminal No. 8 and distributor 6-pin connector terminal No. 2 (component side). (Scheme 186) If resistance is zero ohms, replace distributor assembly. If resistance is not zero ohms, power transistor is okay.

Scheme 186

Scheme 186: POWER TRANSISTOR
Scheme 186: POWER TRANSISTOR
  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. If engine speed does not drop as each cylinder is tested, testing is complete. If engine speed does drop as each cylinder is tested, go to step 8.
  3. Start engine and allow to idle. Let engine idle. Backprobing at ECM, connect an oscilloscope between ground and ECM terminals No. 21, 22, 23 and 23 and read waveform signal voltage. (Scheme 134) Compare waveform to waveform (Scheme 187) If waveform is the same, testing is complete. If waveform is not the same, go to step 8.
  4. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminals No. 109 and 111 (Red/Green wire). If battery voltage exists, leave ignition on and go to next step. If battery voltage does not exist, check power supply for ECM. See «POWER & GROUND CIRCUITS (ALTIMA & SENTRA 2.5L)»(ref-135812-S14719254902002022500000) under COMPUTERIZED ENGINE CONTROLS.
  5. Backprobing at ECM, measure voltage between ground and ECM harness connector terminals No. 12 (Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, check power supply for ECM. See «POWER & GROUND CIRCUITS (ALTIMA & SENTRA 2.5L)»(ref-135812-S14719254902002022500000) under COMPUTERIZED ENGINE CONTROLS.
  6. Turn ignition off. Disconnect ignition condenser 2-pin harness connector. Check continuity of Red wire between ECM harness connector terminal No. 12 and condenser + terminal. See «WIRING DIAGRAMS»(ref-135817) article. Also, check continuity of Black wire between ground and condenser - terminal. Continuity should exist at each measurement. Check circuit for short to ground and short to voltage. If no problem is found, go to next step. If problem is found, repair circuit as necessary. After repair, retest system.
  7. Check ignition condenser. See «IGNITION CONDENSER»(ref-135812-S11397721702002022500000). If no problem is found, go to next step. If problem is found, replace condenser.
  8. Turn ignition off. Reconnect any disconnected harness connectors. Disconnect suspect ignition coil 3-pin harness connector. Turn ignition on. Measure voltage between ground and ignition coil harness connector terminal No. 3 (Red wire). (Scheme 188) If battery voltage exists, leave harness connector disconnected and go to step 10. If battery voltage does not exist, go to next step.
  9. For Altima, check following: Check for open or short between suspect ignition coil and Intelligent Power Distribution Module (IPDM). See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect ignition coil and ECM. For Sentra, check following: Check for open or short between suspect ignition coil and ECM relay. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect ignition coil and ECM. If problem is found, repair as necessary. After repair, retest system.
  10. Turn ignition off. Check continuity in Black wire between ground and suspect ignition coil harness connector terminal No. 2. (Scheme 188) Continuity should exist. Also, check harness for short to voltage. If no problem is found, leave ignition off and go to next step. If problem is found, repair as necessary. After repair, retest system.
  11. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132)or (Scheme 133). Check continuity between ignition coil terminal No. 1 and ECM harness connector terminals No. 21, 22, 23 and 24. (Scheme 134)and (Scheme 188). Continuity should exist at each measurement. Also, check circuits for short to ground or short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  12. Check ignition coil with power transistor. See «IGNITION COIL WITH POWER TRANSISTOR»(ref-135812-S09287470032002022500000). If no problem is found, go to next step. If problem is found, replace suspect ignition coil.
  13. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 187

Scheme 187
Scheme 187

Scheme 188

Scheme 188
Scheme 188
  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. If engine speed drops as each cylinder is tested, testing is complete. If engine speed does not drop as each cylinder is tested, go to step 10.
  3. Start engine and allow to idle. Backprobing at ECM, connect an oscilloscope between ground and ECM terminals No. 5, 6, 7, 15, 16 and 17 and read waveform signal voltage. (Scheme 134) Compare waveform to waveform (Scheme 187) If waveform is the same, testing is complete. If waveform is not the same, go to step 10.
  4. Turn ignition off, wait 10 seconds and turn ignition on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminals No. 110 and 112 (Red/Green wire). If battery voltage exists, leave ignition on and go to next step. If battery voltage does not exist, check power supply for ECM. See «POWER & GROUND CIRCUITS (ALTIMA 3.5L)»(ref-135812-S16750250862002102800000) under COMPUTERIZED ENGINE CONTROLS.
  5. Backprobing at ECM, measure voltage between ground and ECM harness connector terminals No. 31 (Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, check power supply for ECM. See «POWER & GROUND CIRCUITS (ALTIMA 3.5L)»(ref-135812-S16750250862002102800000) under COMPUTERIZED ENGINE CONTROLS.
  6. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Disconnect Intelligent Power Distribution Module (IPDM) 12-pin harness connector E122. IPDM is located at right front corner of engine compartment. Check continuity of Red wire between ECM harness connector terminal No. 31 and IPDM harness connector terminal No. 35. (Scheme 134)and (Scheme 144). Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, leave harness connector disconnected and go to next step. If no problem is found, replace IPDM. After repair, retest system.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E27 and E130. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and E32. Check for open or short in circuits between ECM and IPDM. If problem is found, repair as necessary. After repair, retest system. If no problem is found, leave ECM harness connector disconnected and go to next step.
  8. Turn ignition off. Disconnect condenser 2-pin harness connector. Condenser is located on wiring harness along side of intake manifold collector, near vacuum reservoir. Check continuity of Red wire between ECM harness connector terminal No. 12 and condenser + terminal. Check continuity of Black wire between ground and condenser - terminal. See «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist at each measurement. Also, check circuit for short to ground and short to voltage. If no problem is found, go to next step. If problem is found, repair circuit as necessary. After repair, retest system.
  9. Check ignition condenser. See «IGNITION CONDENSER»(ref-135812-S11397721702002022500000). If no problem is found, go to next step. If problem is found, replace condenser.
  10. Turn ignition off. Reconnect any disconnected harness connectors. Disconnect suspect ignition coil 3-pin harness connector. Turn ignition on. Measure voltage between ground and ignition coil harness connector terminal No. 3 (Red wire). (Scheme 188) If battery voltage exists, leave harness connector disconnected and go to step 12. If battery voltage does not exist, go to next step.
  11. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F43 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect ignition coil and ECM. Check for open or short between suspect ignition coil and harness connector F32. If problem is found, repair as necessary. After repair, retest system.
  12. Turn ignition off. Check continuity in Black wire between ground and suspect ignition coil harness connector terminal No. 2. (Scheme 188) Continuity should exist. Also, check harness for short to voltage. If no problem is found, leave ignition off and go to next step. If problem is found, repair as necessary. After repair, retest system.
  13. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F43 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect ignition coil and ECM. If problem is found, repair as necessary. After repair, retest system.
  14. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132)or (Scheme 133). Check continuity between ignition coil harness connector terminal No. 1 and ECM harness connector terminals No. 5, 6, 7, 15, 16 and 17. (Scheme 134)and (Scheme 188). Continuity should exist at each measurement. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 16.
  15. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F43 and F201. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short between suspect ignition coil and ECM. If problem is found, repair as necessary. After repair, retest system.
  16. Check ignition coil with power transistor. See «IGNITION COIL WITH POWER TRANSISTOR»(ref-135812-S09287470032002022500000). If no problem is found, go to next step. If problem is found, replace suspect ignition coil. After repair retest system.
  17. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. If engine speed does not drop as each cylinder is tested, go to step 12. If engine speed drops as each cylinder is tested, go to step 7.
  3. Let engine idle. Backprobing at ECM, connect an oscilloscope between ground and ECM terminal No. 1 (Purple/White wire) and read waveform signal voltage. (Scheme 145)and (Scheme 146). Compare waveform to waveform (Scheme 189) If waveform is the same, go to step 12. If waveform is not the same, go to step 7.
  4. Turn ignition off. Disconnect distributor 2-pin harness connector F17 (ignition coil connector). Turn ignition on. Measure voltage between ground and ignition coil harness connector terminal No. 7 (Black/White wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E43 and M65. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F27 and M59. Check for open or short in Black/White wire between ignition coil and ignition switch. If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition off. Disconnect distributor power transistor 6-pin harness connector F13. Check continuity between ground and distributor power transistor harness connector F13 terminal No. 2 (Black/Red wire). (Scheme 190) Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair circuit as necessary. After repair, retest system. If no problem is found, leave harness connector disconnected and go to next step.
  7. Turn ignition off. Disconnect ECM 124-pin harness connector. For ECM location (Scheme 145) Check continuity of Purple/White wire between ECM harness connector terminal No. 1 and distributor power transistor harness connector terminal No. 1. (Scheme 146)and (Scheme 190). Continuity should exist. Also, check circuit for short to ground and short to voltage. If problem is found, repair circuit as necessary. After repair, retest system. If no problem is found, go to next step.
  8. Check ignition coil. See «IGNITION COIL»(ref-135812-S16154584042002022500000). If ignition coil tests okay, go to next step. If ignition coil does not test okay, replace distributor assembly.
  9. Check power transistor. See «POWER TRANSISTOR»(ref-135812-S14660649872002022500000). If power transistor tests okay, go to next step. If power transistor does not test okay, replace distributor assembly.
  10. Turn ignition off. Disconnect distributor 2-pin harness connector (ignition coil connector). Remove tape covering resistor. (Scheme 191) Disconnect resistor 2-pin harness connector. Check continuity of Black/Red wire between resistor harness connector terminal No. 1 and distributor 2-pin harness connector terminal No. 8. Backprobing at ECM, check continuity of Black wire between resistor harness connector terminal No. 2 and ECM harness connector terminal No. 2. (Scheme 146)and «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist at both measurements. Also, check circuits for short to ground and short to voltage. If problem is found, repair circuit(s) as necessary. After repair, retest system. If no problem is found, leave resistor harness connector disconnected and go to next step.
  11. Measure resistance between resistor connector terminals (component side). Resistance should be about 2200 ohms at 77°F (25°C). (Scheme 192) If resistance is as specified, go to next step. If resistance is not as specified, replace resistor.
  12. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 189

Scheme 189
Scheme 189

Scheme 190

Scheme 190
Scheme 190

Scheme 191

Scheme 191
Scheme 191

Scheme 192

Scheme 192
Scheme 192
  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 3. If engine does not start, go to step 4.
  2. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. If engine speed drops as each cylinder is tested, testing is complete. If engine speed does not drop as each cylinder is tested, go to step 14.
  3. Start engine and allow to idle. Backprobing at ECM, connect an oscilloscope between ground and ECM terminals No. 5, 6, 7, 15, 16 and 17 and read waveform signal voltage. (Scheme 134) Compare waveform to waveform (Scheme 187) If waveform is the same, testing is complete. If waveform is not the same, go to step 14.
  4. Turn ignition off, wait 10 seconds and turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminals No. 110 and 112 (Red/Green wire). If battery voltage exists, leave ignition on and go to next step. If battery voltage does not exist, check power supply for ECM. See «POWER & GROUND CIRCUITS (I35 & MAXIMA)»(ref-135812-S08860926742002022500000) under COMPUTERIZED ENGINE CONTROLS.
  5. Backprobing at ECM, measure voltage between ground and ECM terminal No. 31 (Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 11.
  6. Turn ignition off. Disconnect ECM relay from underhood fuse and relay panel. For ECM relay location (Scheme 148) Check continuity of Red wire (changes to Red/White at relay) between ECM terminal No. 31 and ECM relay terminal No. 7. (Scheme 134)and (Scheme 175). Continuity should exist. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, leave ECM relay disconnected and go to step 8.
  7. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E15 and F18. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuit between ECM relay and ECM. If problem is found, repair as necessary. After repair, retest system.
  8. Measure voltage between ground and ECM relay harness connector terminal No. 6. (Scheme 175) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 10.
  9. Check following: Check fuse No. 58 (15-amp). Fuse is located in underhood fuse and relay box. Check for open or short in circuit between ECM relay and ECM. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  10. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 149) When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to step 19. Replace relay, if test values are not as specified.
  11. Turn ignition off. Disconnect ignition condenser 2-pin harness connector. Ignition condenser is located at wiring harness along front of intake manifold. Backprobing at ECM, check continuity in Red wire between ECM terminal No. 31 and condenser terminal No. 1. See «WIRING DIAGRAMS»(ref-135817) article. Continuity should exist. Also, check for short to ground or short to voltage. If no problem is found, leave condenser harness disconnected and go to next step. If problem is found, repair as necessary. After repair, retest system.
  12. Check continuity of Black wire between ground and ignition condenser harness connector terminal No. 2. If no problem is found, leave condenser harness disconnected and go to next step. If problem is found, repair as necessary. After repair, retest system.
  13. Check condenser. See «IGNITION CONDENSER»(ref-135812-S11397721702002022500000). If no problem is found, go to next step. If problem is found, replace condenser.
  14. Turn ignition off. Connect any disconnected harness connectors. Disconnect suspect ignition coil 3-pin harness connector. Turn ignition on. Measure voltage between ground and ignition coil harness connector terminal No. 3 (Red wire). (Scheme 188) If battery voltage does not exist, go to next step. If battery voltage exists, go to step 16.
  15. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F59 and F221. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between suspect ignition coil and in-line harness connector F18. If problem is found, repair as necessary. After repair, retest system.
  16. Turn ignition off. Check continuity of Black wire between ground and suspect ignition coil harness connector terminal No. 2. (Scheme 188) Continuity should exist. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  17. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 141) Check continuity between ignition coil terminal No. 1 and ECM harness connector terminals No. 21, 22, 23, 30, 31 and 32. (Scheme 134)and (Scheme 188). Continuity should exist at each measurement. Also, check circuits for short to ground or short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  18. Check ignition coil with power transistor. See «IGNITION COIL WITH POWER TRANSISTOR»(ref-135812-S09287470032002022500000). If no problem is found, go to next step. If problem is found, replace suspect ignition coil. After repair retest system.
  19. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step 12. If engine does not start, go to step 3.
  2. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. If engine speed drops as each cylinder is tested, testing is complete. If engine speed does not drop as each cylinder is tested, go to step 12.
  3. Turn ignition off, wait 10 seconds and turn ignition on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminals No. 110 and 112 (Black/White wire). (Scheme 134) If battery voltage exists, leave ignition on and go to next step. If battery voltage does not exist, check power supply for ECM. See «POWER & GROUND CIRCUITS (PATHFINDER & QX4)»(ref-135812-S03366295782002103000000) under COMPUTERIZED ENGINE CONTROLS.
  4. Turn ignition off. Disconnect ignition condenser 2-pin harness connector. Condenser is located on wiring harness along side of intake manifold collector, near vacuum reservoir. Turn ignition on. Measure voltage between ground and ignition condenser harness connector terminal No. 1 (Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, leave harness connector disconnected and go to step 10.
  5. Turn ignition off. Disconnect ECM relay from underhood fuse and relay panel. For ECM relay location (Scheme 148) Check continuity of Red wire between ECM relay and ignition condenser. See «WIRING DIAGRAMS»(ref-135817) article. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, leave ECM relay disconnected and go to step 7.
  6. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F22 and M33. Check for open or short in circuit between ECM relay and ignition condenser. If problem is found, repair as necessary. After repair, retest system.
  7. Measure voltage between ground and ECM relay harness connector terminal No. 5 (Red/White wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 9.
  8. Check following: Check fuse block fuse No. 63 (10-amp). Check for open or short in circuits between ECM relay and fuse. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  9. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. (Scheme 149) When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  10. Turn ignition off. Measure resistance in Black wire between ground and ignition condenser harness connector terminal No. 2. Continuity should exist. Also, check circuit for short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  11. Check condenser. See «IGNITION CONDENSER»(ref-135812-S11397721702002022500000). If no problem is found, go to next step. If problem is found, replace condenser.
  12. Turn ignition off. Connect any disconnected harness connectors. Disconnect suspect ignition coil 3-pin harness connector. Turn ignition on. Measure voltage between ground and suspect ignition coil harness connector terminal No. 3 (Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step 14.
  13. Check for open or short between suspect ignition coil and in-line harness connector F22. See «WIRING DIAGRAMS»(ref-135817) article. If problem is found, repair as necessary. After repair, retest system.
  14. Turn ignition off. Check continuity of Black wire between ground and suspect ignition coil harness connector terminal No. 2. (Scheme 188) Continuity should exist. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  15. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 142) Check continuity between ignition coil terminal No. 1 and ECM harness connector terminals No. 21, 22, 23, 30, 31 and 32. (Scheme 134)and (Scheme 188). Continuity should exist at each measurement. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 17.
  16. Check ignition coil with power transistor. See «IGNITION COIL WITH POWER TRANSISTOR»(ref-135812-S09287470032002022500000). If no problem is found, go to next step. If problem is found, replace suspect ignition coil. After repair retest system.
  17. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

IGNITION CONDENSER DISTRIBUTORLESS IGNITION SYSTEM

Turn ignition off. Disconnect condenser 2-pin harness connector. Using DVOM measure resistance between condenser + and - terminals. Resistance should be 1 m/ohm @ 77°F (25°C).

IGNITION COIL WITH POWER TRANSISTOR DISTRIBUTORLESS IGNITION SYSTEM

Turn ignition off. Disconnect suspect ignition coil 3-pin harness connector. Measure resistance between specified terminals. See CHECKING IGNITION COIL RESISTANCE (ALTIMA & SENTRA 2.5L) or CHECKING IGNITION COIL RESISTANCE (I35, MAXIMA, PATHFINDER & QX4) table. (Scheme 188)

Measure Between TerminalsSpecification @ 77°F (25°C)
1 & 2Except Zero Or Infinity
1 & 3Except Zero
2 & 3Except Zero

CHECKING IGNITION COIL RESISTANCE (ALTIMA & SENTRA 2.5L)

Measure Between TerminalsSpecification @ 77°F (25°C)Result
2 & 3ZeroNo Good
2 & 3Not ZeroGood

CHECKING IGNITION COIL RESISTANCE (I35, MAXIMA, PATHFINDER & QX4)

ECM depends upon crankshaft position sensor for RPM signals. ECM uses signals to determine triggering of power transistors and fuel injectors. To test crankshaft position sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

To test camshaft position sensor, see related DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.

Timing Advance System

ECM controls ignition timing advance based upon sensor input signals that reflect ignition timing needs. If timing problems are experienced, inspect input signals listed below for proper operation. To check input signals, see ENGINE SENSORS & SWITCHES or ECM pin voltage charts in PIN VOLTAGE CHARTS article.

  1. A/C Clutch Signal
  2. Closed Throttle Position Switch
  3. Crankshaft Position Sensor
  4. Engine Coolant Temperature
  5. Ignition (START) Signal
  6. Mass Airflow Sensor
  7. Park/Neutral Switch
  8. Power Steering Pressure Switch
  9. Throttle Position Sensor
  10. Vehicle Speed Sensor

MISCELLANEOUS CONTROLS

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.

A/C CLUTCH RELAY

  1. A/C clutch relay is controlled by ECM. Under normal conditions, ECM will engage clutch relay by providing a ground circuit for relay windings. If ECM receives a wide open throttle signal from throttle position sensor while it is also receiving an A/C on signal from A/C auto amplifier, ECM will disengage relay.
  2. Remove A/C relay located in underhood relay box. Apply battery voltage to terminals No. 1 and 2. (Scheme 147)and (Scheme 149). Continuity should exist between terminals No. 3 and 5. When battery voltage is removed, continuity should not exist. Replace relay if continuity is not as specified.

Electrical load signal (headlights or rear window defogger on) is transferred through CAN communication line from Body Control Module (BCM) to ECM via Intelligent Power Distribution Module (IPDM).

  1. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See «CHECKING REAR WINDOW DEFOGGER LOAD SIGNAL (ALTIMA)»(ref-135812-S06227566852002110100000) table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step 3 . CHECKING REAR WINDOW DEFOGGER LOAD SIGNAL (ALTIMA) Condition Load Signal Rear Window Defogger Switch ON ON Rear Window Defogger Switch OFF OFF
  2. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See «CHECKING LIGHTING SWITCH LOAD SIGNAL (ALTIMA)»(ref-135812-S01985250072002110100000) table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step 4 . CHECKING LIGHTING SWITCH LOAD SIGNAL (ALTIMA) Condition Load Signal Lighting Switch ON At Second Position ON Lighting Switch OFF OFF
  3. Check operation of rear window defogger. See appropriate REAR WINDOW DEFOGGERS article in ACCESSORIES & EQUIPMENT.
  4. Check operation of headlamp system. See appropriate HEADLIGHT SYSTEMS article in ACCESSORIES & EQUIPMENT.
  1. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 51 (White/Green wire). (Scheme 134)and (Scheme 141). Turn rear window defogger On and Off. With rear window defogger on, battery voltage should exist. With rear window defogger off, zero volts should exist. If voltage is as specified, go to next step. If voltage is not as specified, go to step 3.
  2. Backprobing at ECM, measure voltage between ground and ECM terminal No. 52 (White/Green wire). Turn headlights On and Off. With headlights on, battery voltage should exist. With headlights off, zero volts should exist. If voltage is as specified, go to step 10. If voltage is not as specified, go to step 7.
  3. Check rear window defogger for correct operation. See appropriate REAR WINDOW DEFOGGERS article in ACCESSORIES & EQUIPMENT. If rear window defogger operates normally, go to next step. If rear window defogger does not operate normally, repair as necessary.
  4. Disconnect rear window defogger relay located in underhood relay box. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 134) Connect positive DVOM lead to ECM harness connector terminal No. 51 (White/Green wire) and negative DVOM lead to rear window defogger relay harness connector terminals No. 5 and 7 (Green wires). (Scheme 141)and (Scheme 149). Continuity should exist. Reverse DVOM leads and repeat test. Continuity should not exist. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors B1 and M5. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F68 and M161. Check for poor, loose, corroded or damaged terminal connections in diode M35. Check for open or short in Green/Red wire between ECM and rear window defogger relay. If problem is found, repair as necessary. After repair, retest system.
  6. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  7. Start engine and check headlight high beam operation. See HEADLIGHT SYSTEMS article in ACCESSORIES & EQUIPMENT. If headlights operate normally, go to next step. If headlights do not operate normally, repair as necessary.
  8. Disconnect right headlamp relay located in underhood relay box. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 134) Connect positive DVOM lead to ECM harness connector terminal No. 51 (White/Green wire) and negative DVOM lead to right headlamp relay harness connector terminal No. 5 (Orange/Black wire). (Scheme 141)and (Scheme 149). Continuity should exist. Reverse DVOM leads and repeat test. Continuity should not exist. Also, check circuit for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 10.
  9. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E81 and M15. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F68 and M161. Check for poor, loose, corroded or damaged terminal connections in diode E79. Check for open or short in circuits between ECM and right headlight relay. If problem is found, repair as necessary. After repair, retest system.
  10. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 52 (Purple wire). (Scheme 134)and (Scheme 142). With rear window defogger on, battery voltage should exist. With rear window defogger off, zero volts should exist. If voltage is as specified, go to next step. If voltage is not as specified, go to step 3.
  2. Backprobing at ECM, measure voltage between ground and ECM terminal No. 52 (Purple wire). With headlights on, battery voltage should exist. With headlights off, zero volts should exist. If voltage is as specified, go to step 10. If voltage is not as specified, go to step 7.
  3. Start engine. Check rear window defogger for correct operation. See appropriate REAR WINDOW DEFOGGERS article in ACCESSORIES & EQUIPMENT. If rear window defogger operates normally, go to next step. If rear window defogger does not operate normally, repair as necessary.
  4. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 134) Disconnect rear window defogger relay located in underhood fuse and relay box, located on left side of engine compartment. Connect positive DVOM lead to ECM harness connector terminal No. 52 (Purple wire) and negative DVOM lead to rear window defogger relay harness connector terminal No. 7 (Black/Red wire). (Scheme 149) Continuity should exist. Reverse test leads and repeat test. Continuity should not exist. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 6.
  5. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M33 and F22. Check for poor, loose, corroded or damaged terminal connections in diode M37. Check for open or short in circuits between ECM and rear window defogger relay. If problem is found, repair as necessary. After repair, retest system.
  6. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  7. Start engine and check headlight high beam operation. See HEADLIGHT SYSTEMS article in ACCESSORIES & EQUIPMENT. If headlights operate normally, go to next step. If headlights do not operate normally, repair as necessary.
  8. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 134) Disconnect left headlamp relay located in underhood relay box, on left side of engine compartment. Connect positive DVOM lead to ECM harness connector terminal No. 52 (Purple wire) and negative DVOM lead to left headlamp relay harness connector terminal No. 5 (Red/White wire). (Scheme 134)and (Scheme 175). Continuity should exist. Reverse DVOM leads and repeat test. Continuity should not exist. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 10.
  9. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M33 and F22. Check for poor, loose, corroded or damaged terminal connections in diode E121. Check for open or short in circuits between ECM and left headlamp relay. If problem is found, repair as necessary. After repair, retest system.
  10. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See «CHECKING REAR WINDOW DEFOGGER LOAD SIGNAL (SENTRA)»(ref-135812-S24317936262002103000000) table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step 7. CHECKING REAR WINDOW DEFOGGER LOAD SIGNAL (SENTRA) Condition Load Signal Rear Window Defogger Switch ON ON Rear Window Defogger Switch OFF OFF
  2. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See «CHECKING LIGHTING SWITCH LOAD SIGNAL (SENTRA)»(ref-135812-S19766775752002103000000) table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step 8. CHECKING LIGHTING SWITCH LOAD SIGNAL (SENTRA) Condition Load Signal Lighting Switch ON At First Or Second Position ON Lighting Switch OFF OFF
  3. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See «CHECKING FAN CONTROL SWITCH LOAD SIGNAL (SENTRA)»(ref-135812-S08262251752002103000000) table. If LOAD SIGNAL parameter displays as specified, go to step 16. If parameter is not as specified, go to step 9. CHECKING FAN CONTROL SWITCH LOAD SIGNAL (SENTRA) Condition Load Signal Fan Control Switch ON ON Fan Control Switch OFF OFF
  4. If CONSULT-II is not available. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 50 (Red/White wire). (Scheme 132)and (Scheme 134). With rear window defogger on, battery voltage should exist. With rear window defogger off, zero volts should exist. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7.
  5. If CONSULT-II is not available. Backprobing at ECM, measure voltage between ground and ECM terminal No. 50 (Red/White wire). With lighting switch On in second position, battery voltage should exist. With lighting switch Off, zero volts should exist. If voltage is as specified, go to next step. If voltage is not as specified, go to step 8.
  6. If CONSULT-II is not available. Backprobing at ECM, measure voltage between ground and ECM terminal No. 51 (Light Green/Black wire). With blower fan on, battery voltage should exist. With blower fan off, zero volts should exist. If voltage is as specified, go to step 16. If voltage is not as specified, go to step 9.
  7. Start engine. Turn rear window defogger on. If rear window warms up, go to step 10. If rear window does not warm up, repair rear window defogger. See appropriate REAR WINDOW DEFOGGERS article in ACCESSORIES & EQUIPMENT.
  8. Start engine. Turn headlights on. If headlights illuminate, go to step 12. If headlights do not illuminate, repair lighting system. See HEADLIGHT SYSTEMS article in ACCESSORIES & EQUIPMENT.
  9. Start engine. Turn heater fan on. If fan motor operates, go to step 14. If fan motor does not operate, repair blower motor. See appropriate MANUAL OR AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  10. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Disconnect rear window defogger relay harness connector. (Scheme 177) Connect positive DVOM lead to ECM harness connector terminal No. 50 (Red/White wire) and negative DVOM lead to rear window defogger relay harness connector terminals No. 5 and 7 (Blue/Red wires) and check continuity. (Scheme 134)and (Scheme 149). Continuity should exist. Reverse DVOM leads and check continuity. Continuity should not exist. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 16.
  11. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors B1 and M14. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. Check for poor, loose, corroded or damaged terminal connections in diode M55. Check for open or short in circuits between ECM and rear window defogger relay. If problem is found, repair as necessary. After repair, retest system.
  12. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Disconnect combination switch harness connectors (headlight switch). Connect positive DVOM lead to ECM harness connector terminal No. 50 and negative DVOM lead to combination switch harness connector terminal No. 12 (Red/White wire at ECM changes to White/Red wire at combination switch), and check for continuity. Continuity should exist. Reverse DVOM leads, and check for continuity. Continuity should not exist. See «WIRING DIAGRAMS»(ref-135817) article. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 16.
  13. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E108 and M19. Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M1 and E103. Check for poor, loose, corroded or damaged terminal connections in diode M52. Check for poor, loose, corroded or damaged terminal connections in diode M55. Check for open or short in circuits between ECM and combination switch. If problem is found, repair as necessary. After repair, retest system.
  14. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Disconnect heater fan control switch harness. Check continuity of Light Green/Black wire between heater fan control switch harness connector terminal No. 6 and ECM harness connector terminal No. 51. See «WIRING DIAGRAMS»(ref-135817) article. Check continuity of Black wire between ground and heater fan control switch harness connector terminal No. 5. Continuity should exist at both measurements. Also, check circuits for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step 16.
  15. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M59 and F27. See «WIRING DIAGRAMS»(ref-135817) article. Check for open or short in circuits between ECM and fan control switch. Check for open or short in circuits between body ground and fan control switch. If problem is found, repair as necessary. After repair, retest system.
  16. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.
  1. If CONSULT-II is available, go to next step. If CONSULT-II is not available, go to step 3.
  2. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See «CHECKING LIGHTING SWITCH LOAD SIGNAL (SENTRA 2.5L)»(ref-135812-S28423981302002110100000) table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step 9. CHECKING LIGHTING SWITCH LOAD SIGNAL (SENTRA 2.5L) Condition Load Signal Lighting Switch ON In Second Position ON Lighting Switch OFF OFF
  3. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 53 (Red/White wire). (Scheme 132)and (Scheme 134). With lighting switch on, in second position, battery voltage should exist. With lighting switch off, zero volts should exist. If voltage is as specified, go to step 9. If voltage is not as specified, go to next step.
  4. Start engine. Turn headlight switch to second position. If headlights are illuminated, go to next step. If headlights are not illuminated, repair headlight system. See appropriate HEADLIGHT SYSTEMS & DAYTIME RUNNING LIGHTS article in ACCESSORIES & EQUIPMENT.
  5. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Disconnect lighting switch harness connectors (headlight switch). Connect positive DVOM lead to ECM harness connector terminal No. 53 and negative DVOM lead to lighting switch harness connector terminal No. 9 (Red/White wire at ECM changes to Red/Blue wire at lighting switch), and check for continuity. Move negative DVOM lead to terminal No. 10 (Red/White wire at ECM changes to Red/Yellow wire at lighting switch). Continuity should exist. Reverse DVOM leads, repeat test checking continuity. Continuity should not exist. (Scheme 193) Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 9.
  6. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E108 and M19. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. Check for poor, loose, corroded or damaged terminal connections in diode M55. Check for open or short in circuits between ECM and lighting switch. If problem is found, repair as necessary. After repair, retest system.
  7. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 132) Disconnect lighting switch harness connectors (headlight switch). Connect positive DVOM lead to ECM harness connector terminal No. 53 and negative DVOM lead to lighting switch harness connector terminal No. 10 (Red/White wire at ECM changes to Red/Yellow wire at lighting switch), and check for continuity. (Scheme 132)and (Scheme 134). Reverse DVOM leads and repeat test checking continuity. Continuity should not exist. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step 9.
  8. Check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E108 and M19. See «WIRING DIAGRAMS»(ref-135817) article. Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. Check for poor, loose, corroded or damaged terminal connections in diode M55. Check for open or short in circuits between ECM and lighting switch. If problem is found, repair as necessary. After repair, retest system.
  9. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

Scheme 193

Scheme 193
Scheme 193

Scheme 194

Scheme 194: ELECTRONIC CONTROLLED ENGINE MOUNT
Scheme 194: ELECTRONIC CONTROLLED ENGINE MOUNT
  1. If CONSULT-II is available, start engine and warm to normal operating temperature. Set parking brake and let engine idle. While depressing brake pedal, shift transmission into Drive. On CONSULT-II, select ACTIVE TEST mode and perform ENGINE MOUNTING test. Observe amount of body vibration while switching engine mounts Off and On. At idle, engine vibration should be more noticeable when mounts are on then when mounts are off. If engine mounts perform as specified, go to step 6. If engine mounts do not perform as specified, go to step 3.
  2. If CONSULT-II is not available, start engine and warm to normal operating temperature. Set parking brake and let engine idle. While depressing brake pedal, shift transmission into Drive. Observe body vibration while increasing engine speed to 1000 RPM or more. Turn ignition off. Disconnect front or rear engine mount harness connectors. (Scheme 194) Start engine and allow to idle. Observe body vibration. If body vibration is not more noticeable than vibration observed with engine running at 1000 RPM or more, go to next step. If body vibration is more noticeable than vibration than observed with engine running at 1000 RPM or more, go to step 6.
  3. For Altima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E20 and F32. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 28 (10-amp). Check for open or short in White/Blue wire between electronic controlled engine mount and battery. For I35 and Maxima, check following: Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E15 and F18. See «WIRING DIAGRAMS»(ref-135817) article. Check fuse block fuse No. 59 (15-amp). Check for poor, loose, corroded or damaged terminal connections in joint connector-12. Check for open or short in White/Blue wire between electronic controlled engine mount and battery. If problem is found, repair as necessary. After repair, retest system.
  4. Disconnect ECM 116-pin harness connector. For ECM location (Scheme 133) Check continuity of White wire between front or rear engine mount harness connector terminal No. 1 and ECM harness connector terminal No. 4. (Scheme 134) Check continuity of White/Red wire between front or rear engine mount harness connector terminal No. 2 and ECM harness connector terminal No. 14. Continuity should exist. Also, check circuits for short to ground and short to voltage. If problem is found, repair circuit(s) as necessary. After repair, retest system. If no problem is found, go to next step.
  5. Visually inspect front and rear engine mounts. If problem is found, replace front and/or rear engine mounts as necessary. If no problem is found, go to next step.
  6. No problem is indicated at this time. Problem may be intermittent. See «INTERMITTENTS»(ref-135811-S09892990442002022500000) in TROUBLE SHOOTING - NO CODES article.

RELAYS & SOLENOIDS

Note. For ECM terminal identification, see PIN VOLTAGE CHARTS article. For harness connector locations, see ENGINE COMPARTMENT HARNESS under CONNECTOR IDENTIFICATION in appropriate SELF DIAGNOSTICS article. For engine performance related component locations, see appropriate figure under COMPONENT LOCATIONS . For vacuum diagram identification, see VACUUM DIAGRAMS article.

See MISCELLANEOUS CONTROLS .

ECM & Fuel Pump Relays

  1. Two types of relays are used: 4-terminal and 6-terminal. For relay location, see «ECM & FUEL PUMP RELAY LOCATIONS»(ref-135812-S17214846342002022500000) table. Remove appropriate relay. Apply battery voltage and ground to terminals No. 1 and 2. (Scheme 147)and (Scheme 149).
  2. On 4-pin relays, continuity should exist between terminals No. 3 and 5. On 6-terminal relays, continuity should exist between terminals No. 3, 5, 6 and 7. On all relays, when battery voltage is removed, continuity should not exist. Replace relay, if test values are not as specified.
ApplicationLocation
Altima
ECM RelayNear ECM
Fuel Pump RelayOn Passenger Compartment Fuse Block
Frontier & Xterra
ECM RelayAbove ECM
Fuel Pump RelayBehind Instrument Panel, Above Parking Brake Lever
I35 & Maxima
ECM RelayIn Underhood Relay Box
Fuel Pump RelayBehind Left Kick Panel
Pathfinder & QX4
ECM Relay & Fuel Pump RelayIn Underhood Relay Box
Quest
ECM RelayAbove ECM
Fuel Pump RelayIn Underhood Relay Box
Sentra
ECM RelayAt Rear Of ECM, Accessible From Behind Glove Box
Fuel Pump RelayBehind Left Kick Panel

ECM & FUEL PUMP RELAY LOCATIONS

SOLENOIDS

Note. For EGR and EVAP system components, see EMISSION SYSTEMS & SUB-SYSTEMS .

More articles — Engine Controls - System & Component Testing - 4 Cyl & V6